For the bookstore of Exercise 1, the manager wants to predict Sales from Number of Sales People

Question:

For the bookstore of Exercise 1, the manager wants to predict Sales from Number of Sales People Working.
a) Find the slope estimate, b1.
b) What does it mean, in this context?
c) Find the intercept, b0.
d) What does it mean, in this context? Is it meaningful?
e) Write down the equation that predicts Sales from Number of Sales People Working.
f) If 18 people are working, what Sales do you predict?
g) If sales are actually $25,000 when 18 people are working, what is the value of the residual?
h) Have we overestimated or underestimated the sales?