Question

Calculate the mean given the frequency table

Answer 1

Answer:

~15.55 is the mean.

Step-by-step explanation:

The class of frequency is given as 0-9, 10-19 and 20-29.

First of all, let us taken middle value of class:

$\dfrac{0+9}{2} = 4.5$

$\dfrac{10+9}{2} = 14.5$

$\dfrac{20+9}{2} = 24.5$

Formula for mean:

$\text{Mean = } \dfrac{\sum (m \times f)}{\sum f}$

where f is the frequency

and m is the mean value calculated in above step (4.5, 14.5 and 24.5)

The frequencies are given as:

4.5 -  24

14.5 - 20

24.5 - 32

Putting the values in above formula:

$Mean = \dfrac{4.5\times 24+14.5\times 20 +24.5\times 32}{24+20+32}\\\Rightarrow \dfrac{108+290+784}{76}\\\Rightarrow \dfrac{1182}{76} \\\Rightarrow 15.55$

Please refer to the attached image that contains the table for calculation of mean.

So, mean = ~15.55