Assume the following table lists campaign spending, in thousands of dollars, by candidates for statewide office and the percentage of the popular vote they received in their respective districts:
Spending
11.5
51.1
17.9
4.9
12.9
20.5
76.4
Percentage
33.4
12.8
61.2
50.2
78.1
14.1
49.9
Does a strong linear correlation exist between campaign spending and percentage of votes received? How do you know?
If a strong linear correlation exists, answer the following:
a.) Find a regression model (ax+b) for percentage of votes received as a function of campaign spending.
b.) If a politician spent $60,000 on a campaign, what percentage of the vote should she expect to receive? Also, is this interpolation or extrapolation? Why?
c.) If a politician received a quarter of the votes, what would you expect the campaign to have spent?