question_answer

The mean of the following frequency distribution is 57.6 and the sum of the observation is 50. Find the missing frequencies of \[{{f}_{1}}\] and \[{{f}_{2}}\].

Class interval	0-20	20-40	40-60	60-80	80-100	100-120
Frequency	7	\[{{f}_{1}}\]	12	\[{{f}_{2}}\]	8	5

A)  \[{{f}_{1}}=80\,\,and\,\,{{f}_{2}}=20\]          

B)  \[{{f}_{1}}=4\,\,and\,\,{{f}_{2}}=1\]

C)  \[{{f}_{1}}=8\,\,and\,\,{{f}_{2}}=10\]

D)  \[{{f}_{1}}=18\,\,and\,\,{{f}_{2}}=20\]

E)  None of these