Question

The number of students in grade 4 to grade 8 in a school is listed. The mean deviation of the data is

• A. 4
• B. 7.2
• C. 6

Answer 1

The correct option is C 6

The given data set is

70, 63, 68, 83, 76

Mean deviation = sum of absolute values of deviations from ‘a’ $÷$ number of observations

Here, 'a' is the mean of the data.

The mean of the data set is the sum of the data divided by the number of data values.

Mean = $\frac{sumofalldata}{numberofdata}$

Let us find the mean of the data.

Mean = $\frac{70+63+68+83+76}{5}$

= $\frac{360}{5}$

= 72

Hence, the mean of the data = 72

Mean deviation = $\frac{|70-72|+|63-72|+|68-72|+|83-72|+|76-72|}{5}$

= $\frac{2+9+4+11+4}{5}$

= $\frac{30}{5}$ = 6

Hence, the mean deviation of the data = 6