When selecting explanatory variables to include in a regression ...

[jake]

When selecting explanatory variables to include in a regression
 
  A) you should pick all observable variables available.
  B) you should pick all observable variables that are likely to have a meaningful impact on the dependent variable.
  C) ignore all variables that have t-statistics less than the critical value.
  D) ignore variables that have an R2 less than 1.

Question 2

If average cost is positive
 
  A) marginal cost equals average cost.
  B) marginal cost exceeds average cost.
  C) marginal cost is less average cost.
  D) Not enough information is given.

[momtoalll]

Answer to Question 1

B

Answer to Question 2

D