High School Economics Quiz: Average Cost
20 questions · exam conditions
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Average CostQuestion 1 of 20

A firm is operating at an output level where its marginal cost is equal to its average variable cost, and both are greater than zero. Which of the following statements is the most accurate description of the firm's average variable cost (AVC) at this output level?

The firm's AVC is at its minimum point.
The firm's AVC is rising and approaching its maximum.
The firm's AVC is falling but will soon begin to rise.
The firm's AVC is equal to its average total cost.
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High School Economics Quiz

High School Economics Quiz: Average Cost

Practice Average Cost in High School Economics with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Average Cost, giving you a quick way to practice the rules, question types, and explanations that matter most for High School Economics.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A firm is operating at an output level where its marginal cost is equal to its average variable cost, and both are greater than zero. Which of the following statements is the most accurate description of the firm's average variable cost (AVC) at this output level?

  1. The firm's AVC is at its minimum point. (correct answer)
  2. The firm's AVC is rising and approaching its maximum.
  3. The firm's AVC is falling but will soon begin to rise.
  4. The firm's AVC is equal to its average total cost.
Explanation: The marginal cost (MC) curve intersects the average variable cost (AVC) curve at the AVC curve's lowest point. When MC < AVC, AVC is falling. When MC > AVC, AVC is rising. When MC = AVC, the AVC curve is at its minimum. This is a key feature of the relationship between marginal and average cost curves.

Question 2

A cruise ship is about to depart with empty cabins. The average total cost per passenger is $1,500. The average variable cost per passenger (for food, cleaning, etc.) is $300. A standby passenger offers to pay $500 for a cabin. From a short-run perspective, the cruise line should sell the ticket because:

  1. the price of $500 is much lower than the average total cost of $1,500, attracting goodwill.
  2. any price above zero increases total revenue and is therefore profitable.
  3. the price of $500 exceeds the average variable cost of $300, contributing to fixed costs. (correct answer)
  4. the decision should be based on marginal revenue, which is unknown here.
Explanation: In this scenario, the fixed costs of the voyage (fuel for the ship, crew salaries, etc.) are sunk costs. The decision to sell one more ticket depends on whether the price covers the additional (marginal or average variable) costs. Since the price (500)isgreaterthantheaveragevariablecost(500) is greater than the average variable cost (300), selling the ticket generates a positive contribution margin of 200thathelpstocoverthefixedcosts.RefusingthesalebecausethepriceisbelowATC(200 that helps to cover the fixed costs. Refusing the sale because the price is below ATC (1,500) would be a logical error.

Question 3

A software company sells its product for $30 per license. At its current output of 5,000 licenses, its average total cost is $35, and its average variable cost is $20. In the short run, the company should:

  1. shut down immediately because price is less than average total cost.
  2. continue to produce because price is greater than average variable cost. (correct answer)
  3. increase its price to $35 to cover its average total cost and break even.
  4. decrease production to lower its average total cost back to $30 or less.
Explanation: The firm is currently making a loss because the price (30)isbelowtheaveragetotalcost(30) is below the average total cost (35). However, the short-run shutdown rule states that a firm should continue to operate as long as the price is greater than or equal to its average variable cost. Since the price (30)exceedstheAVC(30) exceeds the AVC (20), each unit sold covers its variable costs and contributes $10 toward paying down fixed costs. Shutting down would result in a larger loss equal to the entire fixed cost.

Question 4

A large, established microchip manufacturer can produce chips at a significantly lower average cost per unit than a new, smaller startup, even though both firms pay the same prices for labor and materials. This cost advantage for the larger firm is most likely a result of:

  1. the law of diminishing marginal returns.
  2. a lower average fixed cost in the short run.
  3. economies of scale. (correct answer)
  4. a higher marginal product of labor.
Explanation: Economies of scale occur when a firm's long-run average total cost decreases as production output increases. Large firms can often achieve this through specialization, bulk purchasing, and more efficient use of capital. Diminishing marginal returns is a short-run concept that explains why costs eventually rise when one input is fixed. While lower AFC is part of the story, economies of scale is the broader, long-run principle that applies here.

Question 5

The market price of wheat, a key ingredient for a commercial bakery, rises permanently. How will this change affect the bakery's short-run cost curves: average total cost (ATC), average variable cost (AVC), and average fixed cost (AFC)?

  1. ATC and AVC will shift up; AFC will remain unchanged. (correct answer)
  2. Only the ATC curve will shift up; AVC and AFC will remain unchanged.
  3. ATC, AVC, and AFC will all shift up.
  4. AVC will shift up; AFC and ATC will remain unchanged.
Explanation: Wheat is a variable input, so its cost is a variable cost. An increase in the price of a variable input will increase total variable cost at every level of output. This causes the average variable cost (AVC) curve to shift upward. Since ATC = AVC + AFC, an increase in AVC will also shift the average total cost (ATC) curve upward. Fixed costs are unaffected, so the AFC curve does not change.

Question 6

A large, global logistics company finds that as it expands its operations into more remote and complex markets, its long-run average total cost per delivery begins to rise. This phenomenon is best described as:

  1. the law of diminishing marginal returns.
  2. diseconomies of scale. (correct answer)
  3. increasing marginal cost.
  4. decreasing average fixed cost.
Explanation: Diseconomies of scale occur when a firm's long-run average total costs increase as it increases its scale of production. This often happens in very large firms due to challenges in management, coordination, and communication. Diminishing marginal returns is a short-run concept where at least one input is fixed.

Question 7

A catering company observes that as it increases the number of meals prepared per day from 300 to 350, its average total cost per meal begins to rise. Which statement must be true over this specific range of output?

  1. The company is experiencing diseconomies of scale.
  2. The total fixed costs of the company must have increased.
  3. The marginal cost of a meal is greater than the average total cost. (correct answer)
  4. The average variable cost per meal must be decreasing.
Explanation: When an average value is rising, it is because the marginal value being added is greater than the current average. Therefore, if the average total cost (ATC) is rising, the marginal cost (MC) of producing those additional meals must be higher than the ATC. Diseconomies of scale is a long-run concept, while this is likely a short-run phenomenon caused by diminishing returns.

Question 8

A firm is producing 500 units of a good. At this output level, its average total cost is $25 and its average variable cost is $15. What is the firm's total fixed cost?

  1. $10
  2. $5,000 (correct answer)
  3. $7,500
  4. $12,500
Explanation: First, calculate the average fixed cost (AFC) using the formula ATC = AVC + AFC. So, AFC = ATC - AVC = $25 - $15 = $10. Second, calculate the total fixed cost (TFC) using the formula TFC = AFC × Quantity. So, TFC = $10 × 500 units = 5,000.DistractorsrepresenttheAFC(5,000. Distractors represent the AFC (10), total variable cost (15x500),andtotalcost(15 x 500), and total cost (25 x 500).

Question 9

A company adopts a new management technique that significantly increases the marginal product of its workers. Holding input prices constant, what is the most likely short-run impact on the company's average variable cost (AVC) and average total cost (ATC) curves?

  1. Both curves will shift upward because the new technique requires costly training.
  2. Both curves will shift downward because labor cost per unit of output decreases. (correct answer)
  3. The curves will not shift, but the firm will move to a lower point on each curve.
  4. The AVC curve will shift down, but the ATC curve will shift up due to implementation costs.
Explanation: An increase in the marginal product of labor means that each worker can produce more output in the same amount of time. This reduces the amount of labor required per unit of output. Since labor is a variable cost, this will lower the average variable cost (AVC). As AVC is a component of average total cost (ATC), the ATC curve will also shift downward.

Question 10

A tech startup has high fixed costs from initial software development but a very low and constant marginal cost for each new user it serves. Which statement best describes the shape of this company's average total cost (ATC) curve as its user base grows?

  1. The ATC curve will be U-shaped, initially falling and then rising.
  2. The ATC curve will be constant because the marginal cost is constant.
  3. The ATC curve will continuously decrease, approaching the marginal cost. (correct answer)
  4. The ATC curve will be identical to the average fixed cost curve.
Explanation: The firm's average total cost (ATC) is the sum of its average fixed cost (AFC) and average variable cost (AVC). In this case, since marginal cost is constant, AVC is also constant and equal to MC. AFC (TFC/Q) will continuously fall as the user base (Q) grows. Therefore, the ATC curve will be downward sloping, as the falling AFC constantly pulls it down. It will asymptotically approach the constant AVC/MC from above.

Question 11

A company that manufactures electric scooters finds that producing its 101st scooter adds less to its total cost than the average total cost of producing the first 100 scooters. What does this imply about the average total cost (ATC) of producing 101 scooters?

  1. The ATC of 101 scooters is lower than the ATC of 100 scooters. (correct answer)
  2. The ATC of 101 scooters is higher than the ATC of 100 scooters.
  3. The ATC of 101 scooters is equal to the marginal cost of the 101st scooter.
  4. The average fixed cost for 101 scooters must have increased.
Explanation: The cost of producing the 101st scooter is the marginal cost (MC). The question states that MC is less than the average total cost (ATC). When the marginal value is below the average, it pulls the average down. Therefore, the average total cost of producing 101 scooters will be lower than the average total cost of producing 100 scooters.

Question 12

A bakery pays a fixed monthly rent of $2,000. In January, it produced 500 cakes, and in February, it produced 1,000 cakes. Which statement accurately describes the change in the bakery's average fixed cost (AFC) per cake from January to February?

  1. The AFC per cake decreased because total fixed costs were spread over more units. (correct answer)
  2. The AFC per cake remained unchanged because the total rent payment was fixed.
  3. The AFC per cake doubled because the bakery's production doubled.
  4. The AFC per cake decreased by a larger amount than the average variable cost increased.
Explanation: Average fixed cost (AFC) is calculated as Total Fixed Cost (TFC) divided by Quantity (Q). In January, AFC = $2,000 / 500 = $4.00. In February, AFC = $2,000 / 1,000 = $2.00. The AFC decreased as the fixed cost of rent was spread over a larger number of cakes. The distractors represent common misunderstandings of average versus total costs.

Question 13

For a typical firm, as the quantity of output increases, the vertical distance between its average total cost (ATC) curve and its average variable cost (AVC) curve gets progressively smaller. What is the economic reason for this convergence?

  1. Diminishing marginal returns become less impactful at higher output levels.
  2. Total fixed costs are decreasing as the firm produces more output.
  3. Average fixed cost continuously decreases as output increases. (correct answer)
  4. Marginal cost eventually rises and pulls both average cost curves upward.
Explanation: The relationship between the three cost curves is ATC = AVC + AFC. Therefore, the vertical distance between the ATC and AVC curves is equal to the average fixed cost (AFC). Since AFC = Total Fixed Cost / Quantity, as quantity increases, AFC must decrease. This causes the ATC and AVC curves to converge.

Question 14

A bicycle company is currently operating on its short-run average total cost curve (SRATC₁). If the company decides to invest in a larger, more automated factory, it is effectively making a decision that will move it:

  1. down along its current SRATC₁ curve to a point of lower average cost.
  2. up along its long-run average total cost (LRATC) curve.
  3. from its current SRATC₁ curve to a different short-run curve, SRATC₂. (correct answer)
  4. from its short-run average variable cost curve to a long-run one.
Explanation: The long-run average total cost (LRATC) curve is an envelope of many short-run average total cost (SRATC) curves, where each SRATC corresponds to a specific fixed plant size (like a factory). Changing the factory size is a long-run decision that shifts the firm from its original SRATC curve (SRATC₁) to a new one (SRATC₂) that corresponds to the new factory size.

Question 15

A firm is producing at an output level where its average total cost is $80 and its average fixed cost is $30. The marginal cost of producing the next unit is $90. Based on this information, what can be concluded about the firm's average variable cost (AVC) and average total cost (ATC) as production increases by one unit?

  1. Both the AVC and the ATC are rising. (correct answer)
  2. The AVC is rising, but the ATC is falling.
  3. The ATC is rising, but the AVC is falling.
  4. Both the AVC and the ATC are falling.
Explanation: This is a three-step problem. First, find the current AVC: AVC = ATC - AFC = $80 - $30 = $50. Second, analyze ATC: The marginal cost (MC) is $90, which is greater than the ATC of $80. When MC > ATC, the ATC must be rising. Third, analyze AVC: The marginal cost (MC) is $90, which is greater than the AVC of $50. When MC > AVC, the AVC must be rising. Therefore, both average costs are rising.

Question 16

A manufacturing firm is operating at an output level where its short-run average total cost is at its absolute minimum. Which of the following relationships between costs must be true at this specific level of output?

  1. Average fixed cost is equal to average variable cost.
  2. Marginal cost is equal to average total cost. (correct answer)
  3. Marginal cost is at its own minimum point.
  4. Average total cost is equal to average variable cost.
Explanation: A fundamental property of cost curves is that the marginal cost (MC) curve intersects the average total cost (ATC) curve at the ATC curve's minimum point. If ATC is at its minimum, it is neither rising nor falling, which can only happen when the cost of the next unit (MC) is exactly equal to the current average (ATC).

Question 17

A local pizza parlor's insurance premium, which it must pay monthly regardless of how many pizzas it sells, increases by $300 per month. Assuming the parlor's production level remains the same, what is the immediate effect on its average cost curves?

  1. Average total cost increases, but average variable cost is unchanged. (correct answer)
  2. Both average total cost and average variable cost increase.
  3. Average total cost increases, but marginal cost is unchanged.
  4. Average variable cost increases, but average fixed cost is unchanged.
Explanation: Insurance is a fixed cost because it does not vary with the level of output. An increase in a fixed cost will increase total cost, and therefore average total cost (ATC) and average fixed cost (AFC). It will not affect variable costs, so the average variable cost (AVC) curve remains unchanged. It will also not affect marginal cost (MC), as MC is the change in variable cost.

Question 18

A company's total fixed cost is $2,000. When it produces 40 units of output, its average variable cost is $60. What is the company's average total cost at this level of production?

  1. $50
  2. $60
  3. $110 (correct answer)
  4. $2,400
Explanation: This requires a two-step calculation. First, find the average fixed cost (AFC): AFC = Total Fixed Cost / Quantity = $2,000 / 40 = $50. Second, find the average total cost (ATC) by adding AFC and average variable cost (AVC): ATC = AFC + AVC = $50 + $60 = $110.

Question 19

A firm experiences constant returns to scale. If this firm decides to double all of its inputs in the long run, its total output will double. What will happen to its long-run average total cost?

  1. It will be cut in half.
  2. It will remain the same. (correct answer)
  3. It will double.
  4. It will decrease, but not be cut in half.
Explanation: Constant returns to scale is defined as the situation where a proportional increase in all inputs results in the same proportional increase in output. If inputs double, total costs will double. If output also doubles, the average cost (Total Cost / Output) will remain unchanged. For example, if TC goes from $100 to $200 and Q goes from 10 to 20, the ATC remains $10.

Question 20

A firm observes that as it increases its output from 1,000 to 1,200 units, its average total cost of production decreases. For this range of output, which of the following statements must be true?

  1. The marginal cost of production must be less than the average total cost. (correct answer)
  2. The firm must be experiencing economies of scale.
  3. The average fixed cost must be decreasing faster than average variable cost is increasing.
  4. The total cost of production must be decreasing as output expands.
Explanation: For an average to decrease, the marginal unit added must be less than the previous average. In this context, if the average total cost (ATC) is falling, it must be because the cost of producing the next unit, the marginal cost (MC), is less than the current ATC. While choice C can be true, choice A is the more fundamental and necessary condition.