Question

A survey was conducted to know the number of affected people from Chikungunya in town X. The following table shows the age distribution of cases of Chikungunya admitted during the year in town X.

Age (in year)	Number of cases
0-10	5
10-20	7
20-30	10
30-40	8
40-50	10

The mean age in which Chikungunya occurred during the given year is

• A. 25.5 years
• B. 27.75 years
• C. 29.5 years
• D. 31.5 years

Answer 1

The correct option is B 27.75 years

Age (in years)	No. of cases ($f_i$)	$x_i$	$f_i{x}_i$
0-10	5	5	25
10-20	7	15	105
20-30	10	25	250
30-40	8	35	280
40-50	10	45	450
Total	${\sum }_{i=1}^5{f}_i=40$		${\sum }_{i=1}^5{f}_i{x}_i=1110$

$\therefore$ Mean age, $\overline{x}=\frac{{\sum }_{i=1}^5{f}_i{x}_i}{{\sum }_{i=1}^5{f}_i}$

$=\frac{1110}{40}$

$=27.75years$

Hence, the correct answer is option b.