Calculate the mean deviation of the first five prime numbers.

A.

2.72

B.

5.6

C.

5.25

D.

13.6

Correct answer is A

The first five prime numbers are 2, 3, 5, 7 and 11

M.D = \(\frac {\sum (x - x̄)}{n}\)

n = 5

\(x̄ = \frac {\sum x}{n} = \frac {2 + 3 + 5 + 7 + 11}{5} = \frac {28}{5} = 5.6\)

M.D = \(\frac {(2 - 5.6) + (3 - 5.6) + (5 - 5.6) + (7 - 5.6) + (11 - 5.6)}{5}\)

= \(\frac {(-3.6) + (-2.6) + (-0.6) + (1.4) + (5.4)}{5} = \frac {13.6}{5}\)

Take the absolute value of all numbers in bracket

= \(\frac {3.6 + 2.6 + 0.6 + 1.4 + 5.4}{5} = \frac {13.6}{5}\)

\(\therefore M.D = 2.72\)