Question

Number of goals scored by Ronaldo in champions league for past 10 years are as follows. {1, 3, 8, 4, 7, 6, 10, 12, 17, 10} Find the mean deviation about the mean.

• A. 3
• B. 3.6
• C. 4
• D. 3.4

Answer 1

The correct option is B

3.6

Mean of the given observations = $\frac{1+3+8+4+7+6+10+12+17+10}{10}$

$\overline{x}$ = $\frac{78}{10}$ = 7.8

Absolute deviation of the given observations = {6.8,4.8,0.2,3.8,0.8,1.8,2.2,4.2,9.2,2.2}

${\sum }_{i=1}^{10}|x_i-7.8|$ = 6.8 + 4.8 + 0.2 + 3.8 + 0.8 + 1.8 +2.2 + 4.2 + 9.2 + 2.2 = 36

Therefore mean deviation = $\frac{{\sum }_{i=1}^{10}|x_i-7.8|}{10}$

= $\frac{36}{10}$ = 3.6