Find the mean of this variable.

Question

Consider the following table.
Weekly hours worked                                     Probability
1-30 (average=22)                                          0.08
31-40 (average=35)                                        0.16
41-50 (average=46)                                        0.72
51 and over (average=61)                               0.04


Find the mean of this variable.
A. 42.9
B. 41.0
C. 44.2
D. 49.2

Answer 1

The mean of this variable can be calculated by taking the sum of all the averages x their probability:

22 x .08 = 1.76

35 x .16 = 5.6

46 x .72 = 33.12

61 x .04 = 2.44

1.76+5.6+33.12+2.44 = 42.92

Answer: A