Managerial Economics Problem Set 4 1) Based on your knowledge of the definition of the various measures of short-run cost, complete this table. Q TC TFC TVC AC AFC AVC MC 0 120 [A] [B] - - - - 1 [C] [D] [E] 265 [F] [G] [H] 2) Consider the following cost equation: Total Cost (TC) = 160Q -10Q2 + 1.2Q3. What is Total Cost when the Quantity is 20? 3) Which of the following represents the equation for the Average Cost (AC)? AC = 160 – 10Q + 1.2Q2 AC = 160Q – 10Q + 1.2Q AC = 80Q – 5Q2 + 0.6Q3 AC = 53.3Q – 3.3Q2 + 0.4Q3 4) What is the Marginal Cost of producing the 21st unit? (Hint: Begin by calculating TC at 20 and at 21.) 5) Questions 5 through 7 refer to the following graphical representation of a short-run situation faced by a perfectly competitive firm. Is this a good market for this firm to be in? Yes the firm should be here in the short run but in the long run it should leave. Yes the firm should be here in the short run and it should also stay in the long run. No; the firm should exit immediately. 6) Which of the following describes the firm’s situation in the short run? The firm is breaking even There is a short run loss There is a short run profit The short run profit/loss situation cannot be determined from this graph 7) What do you expect to happen in the long run? New firms will enter; short-run profits will disappear New firms will enter; short-run losses will disappear Some existing firms will leave; short-run profits will disappear Some existing firms will leave; short-run losses will disappear 8) The Automotive Supply Company has a small plant that produces speedometers exclusively. Its annual fixed costs are $30,000, and its variable costs are $10/unit. It can sell a speedometer for $25. How many speedometers must the company sell to break even? 9) What is the break-even revenue? 10) The company sold 3,000 units last year. What was its profit? 11) Next year’s fixed costs are expected to rise to $37,500. What will be the break-even quantity? 12) If the company will sell the number of units obtained in the previous question (number 11) and wants to maintain the same profit as last year, what will its new price need to be? ...

1. Managerial Economics
Problem Set 4
1) Based on your knowledge of the definition of the various
measures of short-run cost, complete this table.
Q
TC
TFC
TVC
AC
AFC
AVC
MC
0
120
[A]
[B]
-
-
-
-
1
[C]
[D]
[E]
265
[F]
[G]
[H]
2) Consider the following cost equation: Total Cost (TC) =
160Q -10Q2 + 1.2Q3. What is Total Cost when the Quantity is
20?
3) Which of the following represents the equation for the

2. Average Cost (AC)?
AC = 160 – 10Q + 1.2Q2
AC = 160Q – 10Q + 1.2Q
AC = 80Q – 5Q2 + 0.6Q3
AC = 53.3Q – 3.3Q2 + 0.4Q3
4) What is the Marginal Cost of producing the 21st unit?
(Hint: Begin by calculating TC at 20 and at 21.)
5) Questions 5 through 7 refer to the following graphical
representation of a short-run situation faced by a perfectly
competitive firm.
Is this a good market for this firm to be in?
Yes the firm should be here in the short run but in the long run
it should leave.
Yes the firm should be here in the short run and it should also
stay in the long run.
No; the firm should exit immediately.
6) Which of the following describes the firm’s situation in
the short run?
The firm is breaking even
There is a short run loss
There is a short run profit
The short run profit/loss situation cannot be determined from
this graph
7) What do you expect to happen in the long run?
New firms will enter; short-run profits will disappear
New firms will enter; short-run losses will disappear
Some existing firms will leave; short-run profits will disappear
Some existing firms will leave; short-run losses will disappear
8) The Automotive Supply Company has a small plant that
produces speedometers exclusively. Its annual fixed costs are

3. $30,000, and its variable costs are $10/unit. It can sell a
speedometer for $25. How many speedometers must the
company sell to break even?
9) What is the break-even revenue?
10) The company sold 3,000 units last year. What was its
profit?
11) Next year’s fixed costs are expected to rise to $37,500.
What will be the break-even quantity?
12) If the company will sell the number of units obtained in
the previous question (number 11) and wants to maintain the
same profit as last year, what will its new price need to be?