a. Sales of a certain dry mashed potato mix have been increasing by 18% per year. Current year sales are 72,843 units. What are sales expected to be 2 years from now, in units?

b. If total variable cost was $134 when total cost was $523, what is total variable cost when total cost is $901?

c. What does R^2 (R squared) mean to a researcher who has just used regression to estimate a model? Why does including more variables in a regression never decrease the value of R^2? Given this, how can we know if we are including too many variables in our regression?

d. People in economics, finance, and other fields often talk about leading and lagging indicators. Breaking away from the business world slightly, what would be an example of a leading indicator that a sports team was having a rough season, and what would be a lagging indicator that a sports team had a rough season?