Question: A manufacturer of children's car seats is studying its brand acceptance in Western Canada. A random sample of 25 stores in British Columbia, Alberta and Saskatchewan showed the following distribution of sales last month.

Number Sold Number of Stores

20-29 2

30-39 4

40-49 5

50-59 10

60-69 4

Total 25

a) Construct a histogram of sales.

b) Construct a relative frequency polygon of sales. (Note, add a column of relative frequency distribution table above)

c) Construct a percentage ogive of sales (note, add a column of cumulative percentages to the preceding frequency distribution table.)

d) Does the histogram suggest skewness in the data? If so, in what direction?

e) What percentage of stores sold fewer than 50 car seats.

f) Calculate the mean of car seats sold per store.

g) Use the short-cut formula to calculate the standard deviation of car seats sold per store.