Refer to the graph below. Which point is the break-even point for the firm?

Suppose a monopoly can sell 10 units of output for $21. In order to sell 11 units of output, the price must fall to $20. What is the marginal revenue of the 11th unit?

A) $41 B) $20 C) $10 D) $1 E) $220

In the regression model Yi = β0 + β1Xi + β2Di + β3(Xi × Di) + ui, where X is a continuous variable and D is a binary variable, β3

A) indicates the slope of the regression when D=1. B) has a standard error that is not normally distributed even in large samples since D is not a normally distributed variable. C) indicates the difference in the slopes of the two regressions. D) has no meaning since (Xi × Di) = 0 when Di = 0.