7. Store records show that people who live closer to a store tend to purchase more. The relationship between the distance to the store in miles (X) and the amount a customer spends over the year in dollars (Y) fits the following regression line: Y = -100 X + 1000. If a customer lives 7 miles from the store, what is the predicted amount that the customer spends at the store annually?
9. U.S. News & World Report publishes the average starting salary and the average GMAT score for MBA graduates at each of the top 80 ranked schools in the country. The data fit the following regression line: Y = 288X - 111,408 where X is the average GMAT score for students at a school and Y is the average starting salary for graduates from that same school. What is a proper interpretation of the coefficient 288 in the regression equation?
a. For each additional point in the average GMAT for a school, the average salary of the graduates from that school tends to be $288 higher.
b. If a graduate of a school improves her/his GMAT by an additional point, he/she will make $288 more in salary.
c. Average salary will be within plus or minus $288 from $111,408.
Interpreting the given equation of regression line for the different coefficient values.