A logistic regression model describes how the probability of voting for the Republican candidate in a presidential election depends on x, the voter’s total family income (in thousands of dollars) in the previous year. The prediction equation for a particular sample is
Find the estimated probability of voting for the Republican candidate when
(a) Income = +10,000,
(b) Income = +100,000. Describe how the probability seems to depend on income.
= 0.4493 / 1.4493 = 0.31
= 2.718 / 3.718 = 0.73
The predicted probability of voting Republic can increase quite a bit as income increases.