Question

The marks scored by 5 students in a test for 50 marks are 20, 25, 30, 35, 40. Find the S.D for the marks. If the marks are converted for 100 marks, find the S.D. for newly obtained marks.

Answer 1

Let assumed mean A = 30

C = 5

To convert the values for 100, all the values will be multiplied by 2. Therefore the new values are 40, 50, 60, 70, 80.

Let A = 60,

C = 10

S.D. also be multiplied by 2. It is also true for the division also.