In a math test given to 14 students, marks out of 100 are recorded as 21, 38, 42, 56, 36, 48,29, 44, 22, 32, 63, 64, 72, 74. Find the arithmetic mean.

Correct option is B

Given:

Marks of 14 students = 21, 38, 42, 56, 36, 48, 29, 44, 22, 32, 63, 64, 72, 74

Formula Used:

​$$\text{Arithmetic Mean} = \frac{\text{Sum of all values}}{\text{Number of values}}$$​​

Solution:
Sum of marks = 21 + 38 + 42 + 56 + 36 + 48 + 29 + 44 + 22 + 32 + 63 + 64 + 72 + 74 = 641
Number of students = 14

​$$\text{Mean} = \frac{641}{14} \approx 45.78$$​​

Thus, the correct option is (b)  45.78