# The mean and standard deviation of marks obtained by 50 students of a class in three subjects, Mathematics, Physics and Chemistry are given below:

Subject Mathematics Physics Chemistry

Mean 42 32 40.9

Standard Deviation 12 15 20

Which of the three subjects shows the highest variability in marks and which shows the lowest?

**Solution:**

The standard deviation of mathematics = 12

The standard deviation of Physics = 15

The standard deviation of Chemistry = 20

The coefficient of variation (C.V) is given by standard deviation/mean × 100

C.V (Mathematics)

= 12/42 × 100

= 28.57

C.V (Physics)

= 15/32 × 100

= 46.87

C.V (Chemistry)

= 20/40.9 x 100

= 48.89

The subject with greater C.V is more variable than others.

Therefore,

the highest variability in marks is in Chemistry and the lowest variability in marks is in Mathematics

NCERT Solutions Class 11 Maths Chapter 15 Exercise ME Question 6

## The mean and standard deviation of marks obtained by 50 students of a class in three subjects, Mathematics, Physics and Chemistry are given below: Which of the three subjects shows the highest variability in marks and which shows the lowest?

**Summary**:

From the given data, the highest variability in marks is in chemistry and the lowest variability in marks is in mathematics