May Brothers Department Store has constructed a survey to learn purchasing intentions of a sample of sixty-two department store customers. The survey asked each customer their household gross income (in thousands of
s), the number of people living in the household, and the number of shopping trips they take per year. The regression results follow (with t-statistics in parenthesis):
TRIP = 0.5 + 0.1 INCOME + 2.0 FAMILY
(1.6) (2.5) (1.5)
R-squared = .85 F-Stat = 120.4 n = 62
Should you include both INCOME and FAMILY in the model, why? If an individual makes $30,000 a year and 4 people live in the household how many trips does your model estimate they will take?