# A random sample of 24 people is classified in the following table according to their ages: Age Frequency 10 – 20 4 20 – 30 6 30 – 40 8 40 – 50 2 50 -

30 views

closed

A random sample of 24 people is classified in the following table according to their ages:

 Age Frequency 10 – 20 4 20 – 30 6 30 – 40 8 40 – 50 2 50 - 60 4

What is the mean age of this group of people?

1. 25
2. 33.3
3. 16.67
4. 54.54

by (30.0k points)
selected

Correct Answer - Option 2 : 33.3

Concept:

• ${\rm{Mean}} = \frac{{\sum {\rm{xf}}}}{{\sum {\rm{f}}}}$

Calculation:

 Age Frequency (f) x xf 10 – 20 4 15 60 20 – 30 6 25 150 30 – 40 8 35 280 40 – 50 2 45 90 50 - 60 4 55 220 $\sum {\rm{f}} = 24$ $\sum {\rm{xf}} = 800$

We know that, ${\rm{Mean}} = \frac{{\sum {\rm{xf}}}}{{\sum {\rm{f}}}}$

$\therefore {\rm{Mean}} = \frac{{800}}{{24}} = 33.3$