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: Option A
Explanation
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