If m and n are the mean and median respectively of the set of numbers 2, 3, 9, 7, 6, 7, 8, 5, find m + 2n to the nearest whole number

A.

19

B.

18

C.

13

D.

12

Correct answer is A

mean(x) = \(\frac{\sum x}{N}\)

= \(\frac{48}{8}\)

= 5.875

re-arranging the numbers;

2, 3, 5, 6, 2, 7, 8, 9

median = \(\frac{6 + 7}{2}\)

= \(\frac{1}{2}\)

= 6.5

m + 2n = 5.875 + (6.5)2

= 13 + 5.875

= 18.875

= \(\approx\) = 19