JAMB - Mathematics (2007 - No. 7)

What is the mean deviation of 3, 5, 8, 11, 12 and 21?

4.7

3.7

Mean \(= \bar{x} = \frac{60}{6} = 10\)
mean deviation \(= \frac{\sum|x-\bar{x}|}{n} = \frac{28}{6}\)
= 4.7