Question

In a company having 80 employees, 60 earn 10.00 per hour and 20 earn 13.00 per hour. The mean earning per hour is $10.75.

a. $20.15
b. $10.75
c. $10.95
d. $11.78

Answer 1

In a company having 80 employees, 60 earn 10.00 per hour and 20 earn 13.00 per hour. The mean earning per hour is.

a. $20.15

b. $10.75

c. $10.95

d. $11.78

Solution

The mean earning per hour is

$$\frac {e _ {1} N _ {1} + e _ {2} N _ {2}}{N},$$

where $e_1, e_2$ - earning per hour for two kinds of employees, $N_1, N_2$ - numbers of two kinds of employees, $N$ - number of all employees.

So we get

$$\frac {60 * 10 + 20 * 13}{80} = 10.75.$$

Answer: b. $10.75.