Math 1280 unit 2

Question

We are given a table for the city of Detroit, Michigan USA for the period of 1961 to 1973 with the following information: a column with the number of full-time police per 100,000 citizens and a column with the number of homicides per 100,000 citizens.

Year	Police	Homicides
1961	260.35	8.6
1962	269.8	8.9
1963	272.04	8.52
1964	272.96	8.89
1965	272.51	13.07
1966	261.34	14.57
1967	268.89	21.36
1968	295.99	28.03
1969	319.87	31.49
1970	341.43	37.39
1971	356.59	46.26
1972	376.69	47.24
1973	390.19	52.33

1. On the same x-axis representing the year, construct the time series of the number of police and the number of homicides on the same graph.
2. Identify the variable that demonstrated the higher percentage increase relative to its initial value (police or homicides), and share your conclusions on the matter.
3. Did the increase in police officers have an impact on the murder rate? Why?

Answer 1

Answer 2

This is just a matter of plotting the data. It could be done like this:

The percentage increase, over the period 1961 to 1973, is calculated as follows:

For police: (390.19 - 260.35)/260.35 = 0.4987 or 49.87%

For homicides: (52.33 - 8.6)/8.6 = 5.0849 or 508.49%

You can see that the increase in the number of police did not affect the number of homicides or at least the data appears to show that.