the following frequency distribution presents the number of
murders (including negligent manslaughter) per 100,000 population
for each U.S. city with population over 250,000 in the year
2011.
Murder Rate Frequency
0.0 β 4.9. 21 5.0 β 9.9
23. 10.0 β 14.9 12
15.0 β 19.9 6
20.0 β 24.9 5
25.0 β 29.9 0 30.0 β 34.9 2
35.0 β 39.9 2.
40.0 β 44.9 0.
45.0 β 49.9 0
50.0 β 54.9. 2
a) How many classes are there?
b) What is the class width?
c) What percentage of cities had murder rates less than 10
per 100,000 population?
d) What percentage of cities had murder rates of 30 or
more per 100,000 population?