Chapter 12, Problem 76H

A researcher is investigating whether population impacts homicide rate. He uses demographic data from Detroit, MI to

compare homicide rates and the number of the population that are white males.

Population Size	Homicide rate per 100,000 people
558,724	8.6
538,584	8.9
519,171	8.5
500,457	8.9
482,418	13.07
465,029	14.57
448,267	21.36
432,109	28.03
416,533	31.49
401,518	37.39
387,046	46.26
373,095	47.24
359,647	52.33

Table 12.27

a. Use your calculator to construct a scatter plot of the data. What should the independent variable be? Why?

b. Use your calculator’s regression function to find the equation of the least-squares regression line. Add this to your

scatter plot.

c. Discuss what the following mean in context.

i. The slope of the regression equation

ii. The y-intercept of the regression equation

iii. The correlation r

iv. The coefficient of determination r2.

d. Do the data provide convincing evidence that there is a linear relationship between population size and homicide

rate? Carry out an appropriate test at a significance level of 0.05 to help answer this question.