According to the table above, if the government sets an effective price ceiling of $20
a. the market will be in equilibrium.
b. the supply will decrease to create equilibrium.
c. the demand will decrease to create equilibrium.
d. the quantity supplied will increase to create equilibrium.
e. the quantity supplied will be 40.

The difference of sample means of two populations is 55.4, and the standard deviation of the difference of sample means is 28.1. which statement is true if we are testing the null hypothesis at the 95% confidence level? a. the difference of the two means is significant, so the null hypothesis must be rejected. b. the difference of the two means is significant, so the null hypothesis must be accepted. c. the difference of the two means is not significant, so the null hypothesis must be rejected. d. the difference of the two means is not significant, so the null hypothesis must be accepted.