Question

in a class there are 50 students . if average marks obtained by the entire class is 42 .find the sum obtained by all his students.​

Answer 1

The sum obtained by all his students is 2100.

Step-by-step explanation:

We are given that in a class there are 50 students.

If the average marks obtained by the entire class is 42 then we have to find the sum obtained by all his students.

Firstly, as we know that the mean (average) of the data is given by the following formula;

                      Mean = $\frac{\text{Sum of all the observations}}{\text{Total number of observations}}$

                                       Or

                           $\bar X=\frac{\sum X}{n}$

where,  $\sum X$  represents the Sum of all the observation in the data.

Now, in the question we are given with $\bar X$ = 42 and Number of observations (n) = 50 students and we have to find  $\sum X$

So,                           $\bar X=\frac{\sum X}{n}$

                               $42=\frac{\sum X}{50}$

                             $\sum X = 50 \times 42$

                                      = 2100

Therefore, the sum obtained by all his students is 2100.