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:
[tex]\dfrac{0+9}{2} = 4.5[/tex]
[tex]\dfrac{10+9}{2} = 14.5[/tex]
[tex]\dfrac{20+9}{2} = 24.5[/tex]
Formula for mean:
[tex]\text{Mean = } \dfrac{\sum (m \times f)}{\sum f}[/tex]
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:
[tex]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[/tex]
Please refer to the attached image that contains the table for calculation of mean.
So, mean = ~15.55
