:
Income (thousands of dollars) Number of families
0 - 20 15
20 - 50 75
50 - 100 60
Suppose you construct a percentage histogram with each horizontal
unit representing one thousand dollars. Then the height of the
rectangle over the first class interval (the one from 0 to 20) is
equal to
a. 0.5
b. 1.0
c. 1.5
d. 2.0
e. 2.5