Question

For a group of 200 students, the mean and standard deviation of the marks are 40 and 15. Find the sum of the squares of the marks.​

Answer 1

Step-by-step explanation:

Incorrect mean is

. There are

candidates.<br>

<br> So,

<br> This is incorrect

as

was misread as

.<br>

Corect

<br>

Correct mean

<br> Now, we will find the correct standard deviation.<br> We know, <br>

<br> When incorrect observations was present, then standard deviation was

.<br>

<br>

<br>

<br> This is the sum when observations were incorrect.<br>

Correct sum

<br>

Correct

<br>

<br> So, the correct standard deviation is

.<br>