A sample of 100 cars driving on a freeway during a morning
commute was drawn, and the number of occupants in each car was recorded. The
results were as follows:
Occupants: 1 2 3 4 5
Number of cars: 76 13 6 3 2
b) standard deviation
d) What proportion of cars had more than the mean number of occupants
e) What proportion of cars was the number of occupants more than one
standard deviation greater than the mean?
f) What proportion of cars was the number of occupants within one standard
deviation of the mean?