Question

If the arithmetic mean of $7,5,13,x$ and $9$ is$10$, then $x$ is$15$.

• A. True
• B. False

Answer 1

The correct option is B False

Find the value of $x$

$$\begin{gathered} Mean\left(\overline{x}\right)=\frac{Sumofallobservations}{Numberofobservations} \\ \therefore 10=\frac{7+5+13+x+9}{5} \\ \Rightarrow 10=\frac{34+x}{5} \\ \Rightarrow 34+x=10\times 5 \\ \Rightarrow 34+x=50 \\ \Rightarrow x=50-34 \\ \Rightarrow x=16 \end{gathered}$$

Therefore, the given statement is false.