#### The daily income of a sample of 50 employees are tabulated as follows : Income (in Rs) 1-200 201-400 401-600 601-800 Number of employees 14 14 14 7   Find the mean daily income of employees.

Solution.  Here we calculate mean by following the given steps:

1. Find the mid point of each interval.
2. Multiply the frequency of each interval by its mid point.
3. Get the sum of all the frequencies (f) and sum of all the (fx)
4.  Now divide sum of (fx) by sum of (f)
Income (in Rs ) xi No.of employees fixi
1-200 100.5 14 1407
201-400 300.5 15 4507.5
401-600 500.5 14 7007
601-800 700.5 7 4903.5

 $\sum f_{i}= 50$

$\sum f_{i}x_{i}= 17825$

$mean\left ( \bar{x} \right )= \frac{\sum f_{i}x_{i}}{\sum f_{i}}= \frac{17825}{50}= 356.5$