Calculate the mean or expected number of cars sold

Question

Using the company records for the past 500 working days, the manager of a car dealership has summarised the number of cars sold per day in the following table:

Number of cars sold per day       Frequency of occurrence

0                                                        40

1                                                       100

2                                                       142

3                                                        66

4                                                        36

5                                                        30

6                                                        26

7                                                        20

8                                                        16

9                                                        14

10                                                       8

11                                                       2

(a) Form the probability distribution for the number of cars sold per day.

(b) Calculate the mean or expected number of cars sold per day.

(c) Calculate the standard deviation of the number of cars sold per day.