10th Class Mathematics Statistics Question Bank

done Statistics and Probability Total Questions - 88

• question_answer1)
  Which one of the following is not central tendency?
  A)
   Mean deviation    done clear
  B)
   Arithmetic mean done clear
  C)
   Median               done clear
  D)
   Mode done clear
  View Solution play_arrow

• question_answer2)
  Which one of the following groups has different class size from others?
  A)
  \[\text{12}0\text{ }\text{ 125}\]                       done clear
  B)
          \[\text{243 }-\text{ 249}\]   done clear
  C)
  \[\text{141}.\text{5 }-\text{ 146}.\text{5}\]         done clear
  D)
   \[\text{315}.\text{5 }-\text{ 32}0.\text{5}\] done clear
  View Solution play_arrow

• question_answer3)
  A student got marks in 5 subjects in a monthly test is given below : 2, 3, 4, 5, 6 in these obtained marks, 4 is the
  A)
   Mean and median   done clear
  B)
   Median but no mean done clear
  C)
   Mean but no median done clear
  D)
   Mode done clear
  View Solution play_arrow

• question_answer4)
  The statistical data are of two types. These types are
  A)
   technical data and presentation data done clear
  B)
   primary data and secondary data   done clear
  C)
   primary data and personal data done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer5)
  The difference between the maximum and the minimum observations in the data is
  A)
   class interval done clear
  B)
   frequency done clear
  C)
   cumulative frequency done clear
  D)
   range   done clear
  View Solution play_arrow

• question_answer6)
  The number of times a particular item occurs in a class interval is called its
  A)
   mean done clear
  B)
   frequency   done clear
  C)
   cumulative frequency done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer7)
  If the mean of \[\text{x}\]and \[\frac{1}{x}\] is M, then the mean of \[{{\text{x}}^{3}}and\,\,\frac{1}{{{x}^{3}}}\]
  A)
   \[\frac{M({{M}^{2}}-3)}{2}\]                      done clear
  B)
  \[N(4{{M}^{2}}-3)\]   done clear
  C)
  \[{{\text{M}}^{\text{3}}}\]                          done clear
  D)
          \[{{\text{M}}^{\text{3}}}+\text{3}\] done clear
  View Solution play_arrow

• question_answer8)
  Allocations to various sectors of the yearly budget t for Rs. 1000 crore are represented by the following pie diagram. The expenditure (in rupees) on agriculture is
  A)
   250 crore            done clear
  B)
          150 crore done clear
  C)
   300 crore                            done clear
  D)
   200 crore   done clear
  View Solution play_arrow

• question_answer9)
  The average weight of 10 men is decreased by 3 kg when one of them whose weight is 80 kg is replaced by a new person. The weight of the new person is
  A)
   70                          done clear
  B)
          60 done clear
  C)
   50                            done clear
  D)
          73 done clear
  View Solution play_arrow

• question_answer10)
  The geometric mean of two numbers a and b is 8 and their harmonic mean is 6.4. The numbers are
  A)
   2.8                         done clear
  B)
          4.16   done clear
  C)
   4.8                         done clear
  D)
          2.16 done clear
  View Solution play_arrow

• question_answer11)
  The mean of the following frequency distribution is

  Class Interval	Frequency
  0 - 10	4
  10 - 20	6
  20 - 30	10
  30 - 40	16
  40 - 50	14

  A)
   25                          done clear
  B)
          35 done clear
  C)
   30                          done clear
  D)
          31   done clear
  View Solution play_arrow

• question_answer12)
  What is the mode from the following table?

  Marks obtained	Frequency
  3	7
  1	11
  23	15
  33	8
  43	3

  A)
   13                                          done clear
  B)
   43 done clear
  C)
   33                          done clear
  D)
          23   done clear
  View Solution play_arrow

• question_answer13)
  \[\overline{x}=a+\frac{\sum fd}{N}\]is the formula of
  A)
   Median          done clear
  B)
          Mode done clear
  C)
   Arithmetic mean   done clear
  D)
         Mean deviation done clear
  View Solution play_arrow

• question_answer14)
  The Sturges rule for determining the number of classes (n) in a frequency distribution with total frequency N is
  A)
   \[\text{n }=\text{ 1 }+\text{ 2}.\text{3 log N}\] done clear
  B)
   \[\text{N }=\text{ 1 }+\text{ 3}.\text{3 log N}\] done clear
  C)
   \[\text{n }=\text{ 1 }+\text{ 3}.\text{3 log N}\]   done clear
  D)
   \[\text{n }=\text{1}-\text{3}.\text{3 log N}\] done clear
  View Solution play_arrow

• question_answer15)
  If the class intervals in a frequency distribution are \[\left( \text{72}-\text{73}.\text{9} \right),\left( \text{74}-\text{75}.\text{9} \right),\left( \text{76}-\text{77}.\text{9} \right),\left( \text{78}-\text{79}.\text{9} \right)\]etc., then the mid-point of the class (74-75.9) is
  A)
   74.50                    done clear
  B)
          74.90 done clear
  C)
   74.95                      done clear
  D)
          75.00 done clear
  View Solution play_arrow

• question_answer16)
  The given histogram shows a frequency distribution of marks obtained by 56 students in a subject. Number of students securing marks between 70 and 100 is
  A)
   2                                             done clear
  B)
   4 done clear
  C)
   6                               done clear
  D)
          8 done clear
  View Solution play_arrow

• question_answer17)
  What is the sum of the frequencies of the intervals 40-50 and 50-60?
  A)
   15                                            done clear
  B)
   25 done clear
  C)
   45                          done clear
  D)
          20 done clear
  View Solution play_arrow

• question_answer18)
  Mean of twenty observations is 15. If two observations 3 and 14 replaced by 8 and 9 respectively, then the new mean will be
  A)
   14                                          done clear
  B)
   15   done clear
  C)
   16                                          done clear
  D)
   17 done clear
  View Solution play_arrow

• question_answer19)
   

  Factory A	Factory B
  No. of wage earners   250	200
  Average daily wage   Rs. 2.00	Rs.2.50

  The average of daily wages for the earners of the two factories combined is
  A)
   Rs. 2.12 done clear
  B)
   Rs. 2.06 done clear
  C)
   Rs. 2.20   done clear
  D)
   Rs. 2.22 done clear
  View Solution play_arrow

• question_answer20)
  Kavita obtained 16, 14, 18 and 20 marks (out of 25) in Maths in weekly tests in the month of Jan 2000; then mean marks of Kavita is
  A)
   16 done clear
  B)
   16.5 done clear
  C)
   17   done clear
  D)
   17.5 done clear
  View Solution play_arrow

• question_answer21)
  Which one of the following is not correct?
  A)
   statistics is liable to be misused done clear
  B)
   the data collected by the investigator to be used by himself are called primary data done clear
  C)
   statistical laws are exact   done clear
  D)
   statistics do not take into account of individual cases done clear
  View Solution play_arrow

• question_answer22)
  The weighted arithmetic mean of the first n natural numbers whose weights are equal to the corresponding numbers is given by
  A)
   \[\frac{1}{2}(n+1)\]        done clear
  B)
          \[\frac{1}{2}(n+2)\] done clear
  C)
   \[\frac{1}{3}(2n+1)\]       done clear
  D)
          \[\frac{1}{3}n(2n+1)\] done clear
  View Solution play_arrow

• question_answer23)
  If the mean of \[{{X}_{1}}\] and \[{{X}_{2}}\] is \[{{M}_{1}}\], and that of \[{{\text{X}}_{1}},{{\text{X}}_{2}},{{\text{X}}_{\text{3}}},{{\text{X}}_{\text{4}}}\]is \[{{M}_{2}}\], the mean of \[{{\text{X}}_{1}}\],\[\frac{{{\text{X}}_{2}}}{a}\],\[{{\text{X}}_{\text{3}}}+a\]\[{{\text{X}}_{\text{4}}}\text{- a}\] is
  A)
   \[{{M}_{2}}+\frac{(a-1)({{x}_{1}}-2{{M}_{1}})}{4a}\]   done clear
  B)
   \[{{M}_{1}}+\frac{(a-1){{x}_{1}}+2{{M}_{2}}}{4a}\] done clear
  C)
   \[\frac{{{M}_{2}}}{4a}+(a-1){{x}_{1}}+2{{M}_{1}}\] done clear
  D)
   \[\frac{{{M}_{1}}}{4a}+(a-1){{x}_{2}}+2{{M}_{2}}\] done clear
  View Solution play_arrow

• question_answer24)
  If the mean of x and\[\frac{1}{x}\] is M, then the mean of \[{{x}^{2}}\,\,and\,\,\frac{1}{{{x}^{2}}}\]
  A)
   \[{{M}^{2}}\]                                    done clear
  B)
   \[\frac{{{M}^{2}}}{4}\] done clear
  C)
   \[2{{M}^{2}}-1\]                done clear
  D)
          \[2{{M}^{2}}+1\] done clear
  View Solution play_arrow

• question_answer25)
  The height of 30 boys of a class are given in the following table :

  Height in cm	Frequency
  120 - 129	2
  130 - 139	8
  140 - 149	10
  150 - 159	7
  160 - 169	3

  If by joining of a boy of height 140 cm, the median of the heights is changed from \[{{M}_{1}}\] to \[{{M}_{2}}\], then\[{{M}_{1}}-{{M}_{2}}\]in cm is
  A)
   0.1                                         done clear
  B)
   -0.1 done clear
  C)
   0                                               done clear
  D)
   0.2 done clear
  View Solution play_arrow

• question_answer26)
  The mean of the following natural numbers 1,2,3, ... 10 is
  A)
   6.5                         done clear
  B)
          4.5 done clear
  C)
   5.5                           done clear
  D)
          5.4 done clear
  View Solution play_arrow

• question_answer27)
  The marks awarded to seven students in a school admission test were :

  Mathematics		English
  A	55	35
  B	45	32
  C	75	44
  D	15	50
  E	10	45
  F	40	60
  G	06	40

  Which subject has the better median value?
  A)
   Mathematics done clear
  B)
   English   done clear
  C)
   Both [a] and [b] above done clear
  D)
   None of the above done clear
  View Solution play_arrow

• question_answer28)
  Formula to find mode is
  A)
   Mean - 2 Median done clear
  B)
         3 Median - 2 Mean   done clear
  C)
   3 Median - Mean            done clear
  D)
   Mean + Median done clear
  View Solution play_arrow

• question_answer29)
  If (1 - 100), (101 - 200), (201 - 300), (301 - 400) (401 - 500) and (501 - 600) are the class intervals of a frequency distribution, then the true class width is
  A)
   99                          done clear
  B)
          99.5 done clear
  C)
   100                          done clear
  D)
          100.5 done clear
  View Solution play_arrow

• question_answer30)
  The given component bar diagram shows percentage of marks obtained by a student in different subjects in a test: The height of the line AB from x-axis is
  A)
   21 cm approximately done clear
  B)
   38 cm   done clear
  C)
   86 cm approximately done clear
  D)
   48 cm done clear
  View Solution play_arrow

• question_answer31)
  A family spends Rs. 6,000 p.m. to meet the monthly expenditure. The expenditure has been shown in the given pie diagram. The miscellaneous expenditure is
  A)
   Rs. 2,000                               done clear
  B)
   Rs. 1,500 done clear
  C)
   Rs. 1,200                             done clear
  D)
   Rs.3,000 done clear
  View Solution play_arrow

• question_answer32)
  When 10 is subtracted from all the observations, the mean is reduced to 60% of its value. If 5 is added to all the observations, then the mean will be
  A)
   25             done clear
  B)
                          30   done clear
  C)
   60                          done clear
  D)
          65 done clear
  View Solution play_arrow

• question_answer33)
  Average scores of fifty students in a class is 44. Later on it was found that a score 23 was incorrectly recorded as 73. The correct average score is
  A)
   42                                          done clear
  B)
   43   done clear
  C)
   45                          done clear
  D)
          44 done clear
  View Solution play_arrow

• question_answer34)
  an examination, a candidate scores the following percentage of marks : English ? 44; Hindi ? 58; Maths ? 74; physics ? 61; Chemistry ? 62. If weights 2,4, 4, 5, 3 respectively allotted to these subjects, then the candidate's weighted mean percentage is
  A)
   61                                          done clear
  B)
   61.5   done clear
  C)
   62                          done clear
  D)
          62.5 done clear
  View Solution play_arrow

• question_answer35)
  HI. If the standard deviation for the marks obtained r by a student in monthly tests is 36 then the variance is
  A)
   6                             done clear
  B)
          36 done clear
  C)
   1296                        done clear
  D)
          None of these done clear
  View Solution play_arrow

• question_answer36)
  The mean of the ungrouped data is given by
  A)
  \[\text{Mean}=\frac{\sum xi}{\Sigma f}\]       done clear
  B)
          \[\text{Mean}=\frac{\sum x}{n}\] done clear
  C)
   \[\text{Mean}=\frac{\sum fx}{\Sigma n}\]       done clear
  D)
          \[\text{Mean}=a+\frac{\sum fx}{n}\] done clear
  View Solution play_arrow

• question_answer37)
  A variable x takes the values 0, 1, 2, ...n with frequencies proportional to\[qn\,,\,n{{C}_{1}}.q{{n}^{-1}}.p\], \[n{{C}_{2}}\,qn{{~}^{-2}}.{{p}^{2}}....\]respectively and \[\text{p }+\text{ q }=\text{ 1};\]then the mean is
  A)
  \[\left( \text{n}+\text{q} \right)\text{p}\]          done clear
  B)
          \[\left( \text{n}+\text{p} \right)\text{n}\] done clear
  C)
   np                            done clear
  D)
          \[\text{n}+\text{pq}\] done clear
  View Solution play_arrow

• question_answer38)
  Class intervals in a frequency distribution are (3 - 6), (7 - 10), (11 - 14), (15 - 18) etc. The actual upper limit of the class interval (7 - 10) is
  A)
   \[10+\frac{1}{2}(11-10)\]   done clear
  B)
   \[10-\frac{1}{2}(11-10)\] done clear
  C)
   \[10+\frac{1}{2}(11+10)\] done clear
  D)
   \[10-\frac{1}{2}(11+10)\] done clear
  View Solution play_arrow

• question_answer39)
  The given graph shows the petrol consumption of a country in millions of tons from 1952 to 1962. The approximate percentage increase on the 1952 figure over the next ten years will be
  A)
   25% done clear
  B)
   40% done clear
  C)
   60%   done clear
  D)
   85% done clear
  View Solution play_arrow

• question_answer40)
  The age-specific death rates for a town are given in the following table :

  Age group (Years)	Specific death rate
  0 - 1	85
  1 - 5	46
  5 - 15	20
  15 - 25	12
  25 - 40	18
  40 - 50	24
  50 - 60	33
  60 - 75	40
  75 and above	76

  The curve drawn between ages and specific death rates will be
  A)
   an increasing curve done clear
  B)
   bell-shaped curve done clear
  C)
   J-shaped curve done clear
  D)
   U-shaped curve   done clear
  View Solution play_arrow

• question_answer41)
  If \[{{f}_{1}}\] is the frequency of the variable xi and \[\overline{x}\] is the arithmetic mean, then always
  A)
   \[\sum\limits_{i=1}^{{}}{{{f}_{i}}({{x}_{i}}+\overline{x})=0}\] done clear
  B)
          \[\sum\limits_{i=1}^{{}}{{{f}_{i}}({{x}_{i}}-\overline{x})=0}\]   done clear
  C)
  \[\sum\limits_{i=1}^{n}{{{f}_{i}}{{({{x}_{i}}+\overline{x})}^{2}}=0}\] done clear
  D)
          \[\sum\limits_{i=1}^{n}{{{f}_{i}}{{({{x}_{i}}-\overline{x})}^{2}}=0}\] done clear
  View Solution play_arrow

• question_answer42)
  The mean yearly salary of an employee of a company was Rs. 20,000. If the mean yearly salaries of male and female employees were Rs. 20800 and Rs. 16800 respectively, then the percentages of males and females employed by the company are respectively.
  A)
   80% and 20%       done clear
  B)
          70% and 30% done clear
  C)
   55% and 45%     done clear
  D)
          50% and 50% done clear
  View Solution play_arrow

• question_answer43)
  If the arithmetic mean of n numbers of a series is \[\overline{x}\] and sum of the first (n-1) numbers is k, then which one of the following is the nth number of the series?
  A)
   \[\overline{x}-nk\]                         done clear
  B)
          \[n\overline{x}-k\]   done clear
  C)
   \[k\overline{x}-n\]                         done clear
  D)
          \[nk\overline{x}\] done clear
  View Solution play_arrow

• question_answer44)
  The average monthly income of a four members of a family is Rs. 610.25, after the marriage of one girl the average income of the family becomes Rs. 650.75, then the salary of married girl is
  A)
   Rs. 488.25           done clear
  B)
   Rs. 488.75   done clear
  C)
   Rs. 479.75           done clear
  D)
   Rs. 489.25 done clear
  View Solution play_arrow

• question_answer45)
  The mean of \[{{x}_{1}}\] and \[{{x}_{2}}\] is\[{{M}_{1}}\] and that of \[{{X}_{1}},{{X}_{2}},{{X}_{3}}....\,{{X}_{4}}\]is \[{{M}_{2}}\], then the mean of \[a{{X}_{1}},a{{X}_{2}},\frac{{{x}_{3}}}{a},\frac{{{x}_{4}}}{a}\]is
  A)
   \[\frac{{{M}_{1}}+{{M}_{2}}}{2}\]            done clear
  B)
          \[\frac{a{{M}_{1}}+\left( \frac{{{M}_{2}}}{a} \right)}{2}\] done clear
  C)
   \[\frac{1}{2a}[({{a}^{2}}-1){{M}_{1}}+2{{M}_{2}}]\]   done clear
  D)
   \[\frac{1}{2a}[2({{a}^{2}}-1){{M}_{1}}+{{M}_{2}}]\] done clear
  View Solution play_arrow

• question_answer46)
  The median of 3, 5, 6, x, 9, 15 is 7. The value of x is
  A)
   7                             done clear
  B)
          4 done clear
  C)
   8                               done clear
  D)
          none of these done clear
  View Solution play_arrow

• question_answer47)
  The numbers 4, 6 and 8 are the frequencies (x + 2), x and (x - 1) and if their arithmetic mean is 8, the value of x is
  A)
   7                                             done clear
  B)
   6 done clear
  C)
   9                                             done clear
  D)
   8   done clear
  View Solution play_arrow

• question_answer48)
  The following table gives the frequency distribution of marks obtained by a batch of 20 students

  Marks	5	15	25	35	45
  No. of students	5	4	6	3	2

  In this table the cumulative frequency of 45 is
  A)
   18                          done clear
  B)
          12 done clear
  C)
   20                            done clear
  D)
          8 done clear
  View Solution play_arrow

• question_answer49)
  If the standard deviation of 5, 7, 9 and 11 is 2, then coefficient of variation is
  A)
   15 done clear
  B)
   25   done clear
  C)
   17 done clear
  D)
   19 done clear
  View Solution play_arrow

• question_answer50)
  An orderly distribution of the raw data into certain specified categories is known as
  A)
   Frequency distribution   done clear
  B)
   Frequency done clear
  C)
   Cumulative frequency done clear
  D)
   Primary data done clear
  View Solution play_arrow

• question_answer51)
  The mean of \[{{X}_{1}},{{X}_{2}},...{{X}_{50}}\]is M, if every xi i = 1, 2 ... 50 is replaced by \[\frac{{{x}_{i}}}{50}\] then the mean is
  A)
   \[M\]                   done clear
  B)
          \[M+\frac{1}{50}\] done clear
  C)
   \[\frac{50}{M}\]                              done clear
  D)
          \[\frac{M}{50}\]   done clear
  View Solution play_arrow

• question_answer52)
  If the first five elements of the set xi + 5 \[\text{i }=\text{ 1},\text{ 2},\text{ 3},\text{ }....\text{5}\]and the next five elements are replaced by \[\text{xj}-\text{5},\text{ j}=\text{6 }....\text{ 1}0\]then the mean will change by
  A)
   0                                               done clear
  B)
   5 done clear
  C)
   10                          done clear
  D)
          25 done clear
  View Solution play_arrow

• question_answer53)
  The mean of the cubes of the first n natural numbers is
  A)
   \[\frac{n{{(n+1)}^{2}}}{2}\]                        done clear
  B)
   \[\frac{n{{(n+1)}^{2}}}{4}\]          done clear
  C)
   \[\frac{n(n+1)(n+2)}{8}\] done clear
  D)
          \[{{n}^{2}}+n+1\] done clear
  View Solution play_arrow

• question_answer54)
  If \[M=\frac{{{x}_{1}}+{{x}_{2}}+.....+{{x}_{20}}}{20}\], then the value of\[\sum\limits_{i=1}^{20}{\frac{({{x}_{1}}-M)}{20}}\]is
  A)
   \[\frac{19M}{20}\]          done clear
  B)
          1 done clear
  C)
   0                               done clear
  D)
          \[\frac{1}{20}\] done clear
  View Solution play_arrow

• question_answer55)
  The class mid-points in a frequency distribution table are 125, 132, 139, 146 and 153. The class boundaries of the last class are
  A)
  \[\text{135}.\text{5}-\text{142}.\text{5}\]     done clear
  B)
          \[\text{136}-\text{143}\] done clear
  C)
  \[\text{149}.\text{5}-\text{156}.\text{5}\]             done clear
  D)
   \[\text{15}0-\text{157}\] done clear
  View Solution play_arrow

• question_answer56)
  The frequency distribution of monthly salaries of 500 workers in a factory is given below :

  Wages (Rs.)	No. of workers
  0 - 49	90
  50 - 99	150
  100 - 149	100
  150 - 199	80
  200 - 249	70
  250or more	10

  It is proposed to give an in term relief per month at the rate of 10% of the lower boundary of each class interval or Rs. 10, whichever is more. Then the financial burden (in Rs.) on the part of the factory owner is
  A)
   4100                      done clear
  B)
          4600 done clear
  C)
   5500                      done clear
  D)
          6250   done clear
  View Solution play_arrow

• question_answer57)
  Annual Develop in net Expenditure of a state under different heads is as follows :

  Agriculture	40%
  Education	35%
  Industry	15%
  Misc.	10%

  Which one of the following charts represents this information?
  A)
                                                                done clear
  B)
  done clear
  C)
                                                    done clear
  D)
                  done clear
  View Solution play_arrow

• question_answer58)
  The arithmetic mean of n numbers is x. If the sum of the first (n -1) numbers is k, then the nth number is
  A)
   \[n\overline{x}+k\]        done clear
  B)
          \[n\overline{x}-k\]   done clear
  C)
   \[X-\frac{k}{n}\]              done clear
  D)
          \[\overline{x}+\frac{k}{n}\] done clear
  View Solution play_arrow

• question_answer59)
  The mean of the first n natural numbers is
  A)
   \[\frac{n}{2}\]                                  done clear
  B)
   \[\frac{n+1}{2}\]   done clear
  C)
   \[\frac{n}{2}+1\]             done clear
  D)
          \[\frac{{{n}^{2}}+n+1}{n}\] done clear
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• question_answer60)
  The mean of the squares of the first n natural numbers is
  A)
   \[{{n}^{2}}+1\] done clear
  B)
          \[\frac{{{n}^{4}}+1}{n}\] done clear
  C)
   \[\frac{(n+1)(2n+1)}{6}\]   done clear
  D)
          \[\frac{(n+1)(n+2)}{m}\] done clear
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• question_answer61)
  A school has 20 teachers, one of them retires at the age of 60 years and a new teacher replaces him, this change reduces the average age of the staff by 2 years, the age of new teacher is
  A)
   28 years              done clear
  B)
   25 years done clear
  C)
   20 years            done clear
  D)
          18 years done clear
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• question_answer62)
  Which one of the following definitions is for frequency curve?
  A)
   The polygon formed by joining the middle points of the tops of bars of the histogram done clear
  B)
   A special type of bar graph to represent a frequency distribution. Here the bars are drawn adjacent to each other, class intervals are represented on the horizotnal axis and frequency on the vertical axis. done clear
  C)
   If the class intervals are plotted on the horizontal axis and the cumulative frequencies on the vertical axis against the upper class boundaries then the free hand curve through the points so plotted. done clear
  D)
   The curve formed by joining the middle points of the tops of bars of the histogram.   done clear
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• question_answer63)
  For a given distribution, the arithmetic mean is 10 and the standard deviation is 8. The coefficient of dispersion is given as
  A)
   8                             done clear
  B)
          80 done clear
  C)
   8                               done clear
  D)
          1.25 done clear
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• question_answer64)
  The mean of the following distribution is

  Class	Frequency
  0 - 5	4
  5 - 10	5
  10 - 15	7
  15 - 20	12
  20 - 25	7
  25 - 30	5

  A)
   15                                          done clear
  B)
   16   done clear
  C)
   17                          done clear
  D)
          18 done clear
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• question_answer65)
  The ages (in years) of a family of 6 members are 1, 5, 12, 15, 38 and 40. The standard deviation is found to be 15.9. After 10 years the standard deviation is
  A)
   Increased done clear
  B)
   Decreased done clear
  C)
   Remains same   done clear
  D)
   None of these done clear
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• question_answer66)
  The arithmetic mean of the set of variable \[\text{a},\text{a}+\text{d},\text{a}+\text{2d},\text{a}+\text{3d}...\text{ a}+\text{2nd}\]is
  A)
  \[\text{a}+\text{nd}\]                     done clear
  B)
          \[\text{a}-\text{nd}\] done clear
  C)
  \[\left( \text{a}+\text{n} \right)\text{d}\]          done clear
  D)
         \[~\text{ad}+\text{n}\] done clear
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• question_answer67)
  In tossing a coin, the chance of throwing head and tail alternatively in 3 successive trials is
  A)
   \[\frac{1}{8}\]                  done clear
  B)
          \[\frac{1}{6}\] done clear
  C)
   \[\frac{1}{5}\]                  done clear
  D)
          \[\frac{1}{4}\]   done clear
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• question_answer68)
  The mean of first odd n natural numbers is
  A)
   n                                              done clear
  B)
   2n done clear
  C)
   n + 2                done clear
  D)
          \[\frac{n}{2}\] done clear
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• question_answer69)
  The following numbers are given 61, 62, 63, 61, 63,64, 64, 60, 6^, 63, 64, 65, 66, 64. The, difference between their mean and median is
  A)
   0.4                         done clear
  B)
          0.3   done clear
  C)
   0.2                         done clear
  D)
          0.1 done clear
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• question_answer70)
  Arithmetic mean for the given data is  

  Marks	No. of I students
  0 - 10	5
  10 - 20	10
  20 - 30	25
  30 - 40	30
  40 - 50	20
  50 - 60	10

     
  A)
  55                          done clear
  B)
  35 done clear
  C)
  33                            done clear
  D)
  2 done clear
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• question_answer71)
  The value of \[\sum\limits_{i=1}^{n}{({{x}_{i}}-\overline{x})}\], where \[\overline{x}\] is the arithmetic mean of \[{{x}_{i}}\] is
  A)
   1                             done clear
  B)
          0   done clear
  C)
   \[n\overline{x}\]                             done clear
  D)
          None of these done clear
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• question_answer72)
  The average of 15 numbers is 18. The average of first 8 is 19 and that last 8 is 17, then the 8th number is
  A)
   15           done clear
  B)
   16 done clear
  C)
   18                            done clear
  D)
          20 done clear
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• question_answer73)
  The attendance of a class of 45 boys for 10 days given as 40, 42, 30, 35, 45, 44, 41, 38, 44 and 4? then the mean attendance of a class is
  A)
   39                          done clear
  B)
          40   done clear
  C)
   41                          done clear
  D)
          43 done clear
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• question_answer74)
  The mean of n numbers\[{{x}_{1}},{{x}_{2}}....\,xn\]is M. 'If \[{{X}_{1}}\] is replaced by \[X',\] then the new mean is
  A)
   \[M-{{X}_{1}}+X'\]          done clear
  B)
   \[\frac{(n-1)M+x'}{n}\] done clear
  C)
   \[\frac{nM-{{x}_{1}}+x'}{n}\]       done clear
  D)
          \[\frac{M-{{x}_{1}}+x'}{n}\] done clear
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• question_answer75)
  Which one of the following statements is correct?
  A)
   The standard deviation for a given distribution is the sqtiare of the variance. done clear
  B)
   The standard deviation for a given distribution is the square root of the variance.   done clear
  C)
   The standard deviation for a given distribution is equal to the variance. done clear
  D)
   The standard deviation for a given distribution is half of the variance. done clear
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• question_answer76)
  A candidate obtained the following percentage of marks in an examination English 60, Maths 90, Physics 75, Chemistry 66. If weights 2, 4, 3,3 are allotted to these subjects respectively, then the weight mean is given by
  A)
   \[\frac{\text{6}0+\text{9}0+\text{75}+\text{66}}{\text{2}+\text{4}+\text{3}+\text{3}}\] done clear
  B)
   \[\frac{\text{6}0\times \text{2}+\text{9}0\times \text{4}+\text{75}\times \text{3}+\text{66}\times \text{3}}{\text{2}+\text{4}+\text{3}+\text{3}}\]   done clear
  C)
  \[\frac{\text{6}0\times \text{2}+\text{9}0\times \text{4}+\text{75}\times \text{3}+\text{66}\times \text{3}}{4}\] done clear
  D)
    \[\frac{\text{6}0+\text{9}0+\text{75}+\text{66}}{4}\] done clear
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• question_answer77)
  A student obtained the following marks percentage in an examination : English - 50, Accounts - 75, Economics - 60, B. Std. - 80, Hindi - 55. If weights are 2, 3, 3, 2, 1 respectively allotted to the subjects, his weighted mean is
  A)
   \[\frac{\text{5}0+\text{75}+\text{6}0+\text{8}0+\text{55}}{\text{2}+\text{3}+\text{3}+\text{2}+\text{1}}\] done clear
  B)
  \[\frac{~\left( \text{5}0\times \text{2} \right)+\left( \text{75}\times \text{3} \right)+\left( \text{6}0\times \text{3} \right)+\left( \text{8}0\times \text{2} \right)+\left( \text{55}\times \text{1} \right)}{5}\] done clear
  C)
   \[\frac{\text{5}0\times \text{2}+\text{75}\times \text{3}+\text{6}0\times \text{3}+\text{8}0\times \text{2}+\text{55}\times \text{1}}{\text{2}+\text{3}+\text{3}+\text{2}+\text{1}}\]   done clear
  D)
   none done clear
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• question_answer78)
  The geometric mean of 2, 6, 8, 24 is
  A)
   \[\sqrt{48}=4\sqrt{8}\]                   done clear
  B)
   16 done clear
  C)
   24                          done clear
  D)
          36 done clear
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• question_answer79)
  In an examination, 10 students scored the following marks in Mathematics 35, 19, 28, 32, 63, 02, 47, 31, 13, 98. Its range is
  A)
   2     done clear
  B)
   96   done clear
  C)
   98                          done clear
  D)
          50 done clear
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• question_answer80)
  What is the mean of the following frequency distribution?

  X	5	7	8	9	12
  Y	2	1	5	4	3

  A)
   \[\frac{\text{1}0\times \text{7}\times \text{4}0\times \text{36}\times \text{36}}{\text{2}+\text{1}+\text{5}+\text{4}+\text{3}}\] done clear
  B)
    \[\frac{\text{5}+\text{7}+\text{8}+\text{9}+\text{12}}{\text{2}+\text{1}+\text{5}+\text{4}+\text{3}}\] done clear
  C)
  \[\frac{\left( \text{5}+\text{7}+\text{8}+\text{9}+\text{12} \right)-\left( \text{2}+\text{1}+\text{5}+\text{4}+\text{3} \right)}{\left( \text{5}+\text{7}+\text{8}+\text{9}+\text{12} \right)+\left( \text{2}+\text{1}+\text{5}+\text{4}+\text{3} \right)}\] done clear
  D)
   \[\frac{\text{5}\times \text{2}+\text{7}\times \text{1}+\text{8}\times \text{5}+\text{9}\times \text{4}+\text{12}\times \text{3}}{\text{2}+\text{1}+\text{5}+\text{4}+\text{3}}\]   done clear
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• question_answer81)
  A contractor employed 18 labourers at Rs. 12 per day, 10 labourers at Rs. 13.50 per day, 5 labourers at Rs. 25 per day and 2 labourers at Rs. 42 per day. The average wage of a labourer per day is
  A)
   Rs. 16                     done clear
  B)
          Rs. 20 done clear
  C)
   Rs. 24                   done clear
  D)
          Rs. 28 done clear
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• question_answer82)
  In a class test in English 10 students scored 75 marks, 12 students scored 60 marks, 8 scored 40 marks and 3 scored 30 marks, the mode for their score is
  A)
   75                                          done clear
  B)
   30 done clear
  C)
   60                            done clear
  D)
          25 Refer the figure given below answer the following questions. done clear
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• question_answer83)
  Which class-interval has the minimum frequency?
  A)
   20-30             done clear
  B)
          40-50 done clear
  C)
   50-60                      done clear
  D)
          10-20 done clear
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• question_answer84)
  What is frequency of the class-interval 20-30?
  A)
   25                                          done clear
  B)
   20   done clear
  C)
   5                                             done clear
  D)
   10 done clear
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• question_answer85)
  How many class-intervals have equal frequency?
  A)
   2                               done clear
  B)
          3 done clear
  C)
   1                                             done clear
  D)
   None done clear
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• question_answer86)
  What is the cumulative frequency of the interval 40-50?
  A)
   70                          done clear
  B)
          60 done clear
  C)
   50                          done clear
  D)
          80   done clear
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• question_answer87)
  What is the difference of frequencies of the intervals 30-40 and 40-50?
  A)
   5                             done clear
  B)
          20 done clear
  C)
   15                            done clear
  D)
          25 done clear
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• question_answer88)
  Which class-interval has the maximum frequency?
  A)
   0-10                      done clear
  B)
          30-40 done clear
  C)
   10-20                    done clear
  D)
          40-50   done clear
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