Question

The mean of the following distribution is ____.
$$\begin{array}{ccccc}{x}_i& \text{10}& \text{13}& \text{16}& \text{19}\\ f_i& \text{2}& \text{5}& \text{7}& \text{6}\end{array}$$

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

Answer 1

The correct option is C

15.55

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

Mean $=\frac{\sum f_i{x}_i}{\sum f_i}$

$=\frac{311}{20}$

$=15.55$