Question

If the mean of 6, 7, x, 8, y, 14 is 9, then

(a) x + y = 21
(b) x + y = 19
(c) x − y = 19
(d) x − y = 21

Answer 1

The given observations are 6, 7, x, 8, y, 14.

Mean = 9 (Given)

$$\begin{gathered} \Rightarrow \frac{6+7+x+8+y+14}{6}=9 \\ \Rightarrow 35+x+y=54 \\ \Rightarrow x+y=54-35=19 \end{gathered}$$

Hence, the correct option is (b).