Question

The ten point quiz scores of 10 students are shown in the given plot. Find the value of MAD.


Number of students Quiz scores

• A. 7
• B. 10
• C. 1.4
• D. 5.2

Answer 1

The correct option is C 1.4

The given dot plot is

The given data set is
4, 5, 6, 6, 7, 7, 7, 9, 9, 10

Mean deviation = sum of absolute values of deviations from ‘a’ $÷$ number of observations, where '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 = $\frac{sumofalldata}{numberofdata}$

Mean = $\frac{4+5+6+6+7+7+7+9+9+10}{10}$

= $\frac{70}{10}$

= 7

Mean deviation = $\frac{|7-4|+|7-5|+|7-6|+|7-6|+|7-7|+|7-7|+|7-7+|7-9|+|7-9|+|7-10|}{10}$

= $\frac{3+2+1+1+2+2+3}{10}$

= $\frac{14}{10}$

= 1.4

Hence, MAD of the data = 1.4