Question

The mean of the following distribution is:

$\begin{array}{ccccc}{x}_i& 10& 13& 16& 19\\ f_i& 2& 5& 7& 6\end{array}$

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

Answer 1

The correct option is C

15.55

Average or mean value of the given number of observations is the sum of all the observations divided by the total number of observations.
$\text{Mean}=\frac{\sum x_i{f}_i}{\sum f_i}$

Here,

$\sum x_i$$f_i=20+65+112+114=311$
and
$\sum f_i=20$

$\therefore \text{Mean}=\frac{\sum x_i{f}_i}{\sum f_i}=\frac{311}{20}=15.55$