Question

3. 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 – 4.9. 21 5.0 – 9.9 23.   10.0 – 14.9 12 15.0 – 19.9 6 20.0 – 24.9 5 25.0 – 29.9 0 30.0 – 34.9 2 35.0 – 39.9 2. 40.0 – 44.9 0. 45.0 – 49.9 0 50.0 – 54.9. 2

   1. a) How many classes are there?

   2. b) What is the class width?

   3. c) What percentage of cities had murder rates less than 10 per 100,000 population?

   4. d) What percentage of cities had murder rates of 30 or more per 100,000 population?

Answer 1

(a) there are 11 class

(b)width is 4.9 ( upper limit -lower limit)

(c) there are two class whose murder rate less than 10 these are 0-4.9 , 5-9.9 [these intervals are inclusive type for which both upper limit and lower limit are included in the interval , but exclusive type interval includes only lower limit not upper limit such as 0-10,10-20...like this]

Total frequency is 73, and frequency for this two class is 21+23=44 ; so percentage is (44/73)*100=60.27

(d) frequencies for class with murder rate more than 30 is 2+2+0+0+2=6

So percentage is (6/73)100=8.23