Question

The mean of the following distriution is
$$\begin{array}{ccccc}x& \text{10}& \text{13}& \text{16}& \text{19}\\ f& \text{2}& \text{5}& \text{7}& \text{6}\end{array}$$

• A. 15.2
• B. 15.35
• C. 15.55
• D. 16

Answer 1

The correct option is C 15.55

$$\begin{array}{ccc}x& f& fx\\ \text{10}& \text{2}& \text{20}\\ \text{13}& \text{5}& \text{65}\\ \text{16}& \text{7}& \text{112}\\ \text{19}& \text{6}& \text{114}\\ & N=20& \sum fx=311\end{array}$$

Note that $\overline{x}$ = $\frac{\sum fx}{N}$,
where $\overline{x}$ stands for mean and $N$ stands for the sum of frequencies.
$⟹\overline{x}=\frac{311}{20}=15.55$