You work for Mut the Custard, a frozen custard company. You've collected data on monthly sales (S, number of regular-sized frozen custards per month) the price of your regular-sized frozen custard (P, in dollars), and the population size in the different cities in which your company operates (N, number of people; you currently only have one establishment in each city). You estimate the following regression model: S = a + bP + cN. In your regressions, you usually look for a 10%-or-better level of confidence

What signs do you expect for a, b, and c?

b.Your regression yields the following results:

Adjusted R Square 0.688

Independent Variables Coefficients Standard Error t Stat P-value

Intercept 7763 2125 3.654 0.01469

P -683.55 169.60 -4.030 0.01002

N 0.0009 0.0079 0.109 0.91762

Interpret what these coefficients mean?