Question

If the mean of observations 20, 42, 35, 45 and x is 37, then x =

(a) 43 (b) 42 (c) 44 (d) 45

Answer 1

Given : the mean of the observations 20, 42, 35, 45 and x.
$$\begin{gathered} \mathrm{Mean}\mathrm{of}\mathrm{observations}=\frac{\mathrm{Sum}\mathrm{of}\mathrm{observations}}{\mathrm{Number}\mathrm{of}\mathrm{observations}} \\ \Rightarrow 37=\frac{20+42+35+45+x}{5} \\ \Rightarrow 142+x=185 \\ \Rightarrow x=185-142=43 \end{gathered}$$
Thus, the value of x is 43.
Hence, the correct option is (a).