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  5. Data Handling

7th Class Mathematics Data Handling Question Bank Data Handling

  • question_answer
                Mean of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18, then the correct mean of the observations is

    A)  40                              

    B)  41                  

    C)  42                  

    D)         43                  

    Correct Answer: C

    Solution :

    Incorrect mean of 9 observations = 35 Incorrect sum of 9 observations \[=35\times 9=315\] Since, 81 is misread as 18. So, correct sum of observations \[=315-18+81=378\] \[\therefore \] Correct mean \[=\frac{378}{9}=42\]


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