The following relative frequency distribution summarizes the ages of women who had a child in the last year.
Ages ...... Relative Frequency
15 up to 20 ... 0.10
20 up to 25 ... 0.25
25 up to 30 .... 0.28
30 up to 35 .... 0.24
35 up to 40 .... 0.11
40 up to 45 .... 0.02

a. Assume the relative frequency distribution is based on a sample of 2,000 women. Construct the corresponding frequency distribution, cumulative frequency distribution, and cumulative relative frequency distribution.
b. What percent of the women were at least 25 but less than 30 years old? What percent of the women were younger than 35 years old?
c. Construct a relative frequency polygon. Comment on the shape of the distribution.
d. Construct an ogive. Using the graph, approximate the age of the middle 50% of the distribution.