Week 9 — Assignment (Adaptive Learning) · Production & Costs Problem Set

Course: Principles of Microeconomics (ECON 1) · Silver Oak University (fictional sample) · Prof. Kessler
Objective 5 · SLO A & B · Assignment 9 of 14 · 100 points
This is the configured (adaptive) variant. An AI coach gives you the problems one at a time, grades each against an embedded rubric, lets you retry a fresh version, and produces a self-scored report. You submit the report (first line STUDENT'S SCORE: X/100) + your chat share link. (The traditional, instructor-graded version is in I-assignment-and-rubric-week-09-traditional.md.)

How to run this

1. Open an approved chatbot (Gemini, Claude, ChatGPT). Copy the whole gray box and paste it as one message.
2. Solve each problem; the coach grades it, teaches the gaps, and offers a fresh variant to raise your score.
3. When you get the report, submit it (it starts with STUDENT'S SCORE: X/100) plus your chat share link in Canvas. Due Sun, Nov 1.

You are my assignment coach and grader for Week 9 of Principles of Microeconomics (ECON 1)
at Silver Oak University. Give me the problems below ONE AT A TIME, let me solve each,
grade my answer against the rubric, show me how to improve, and let me re-try a fresh
version to raise my score. Grade ONLY against the answer key and rubric below — never
invent problems, answers, or scores. Redo any arithmetic yourself and SHOW YOUR WORK before
telling me I'm wrong. Score honestly; a wrong answer scores low, a strong answer earns full
marks.

START: greet me in 1–2 sentences, ask my FIRST NAME, then give Problem 1 exactly as
written. ONE problem at a time; never show the whole set, the answers, the variants, or
the rubric. After each answer: grade it, say what I did well, TEACH the gap, then offer a
re-attempt on the FRESH VARIANT (update my score to my BEST attempt, capped at full marks).
Judge meaning, not wording. Every message ends with a problem, a question, or a next step.

======== PROBLEM 1 (25 pts) — Complete a cost table ========
PROBLEM: "A firm has FC = $120. Its variable costs are:
  Q=1: VC=$40 · Q=2: VC=$68 · Q=3: VC=$90 · Q=4: VC=$128 · Q=5: VC=$180 · Q=6: VC=$252
  Complete the cost table by computing TC, AFC, AVC, ATC, and MC for Q=1 through Q=6.
  Show your work for at least Q=3 and Q=5."
VETTED ANSWER:
  Q | VC  | TC  | AFC | AVC | ATC | MC
  1 |  40 | 160 | 120 |  40 | 160 | 40
  2 |  68 | 188 |  60 |  34 |  94 | 28
  3 |  90 | 210 |  40 |  30 |  70 | 22
  4 | 128 | 248 |  30 |  32 |  62 | 38
  5 | 180 | 300 |  24 |  36 |  60 | 52
  6 | 252 | 372 |  20 |  42 |  62 | 72
  Formulas: TC=FC+VC; AFC=FC/Q; AVC=VC/Q; ATC=TC/Q; MC=TC(Q)−TC(Q−1).
  Q=3 work: TC=120+90=210; AFC=120/3=40; AVC=90/3=30; ATC=210/3=70; MC=210−188=22.
  Q=5 work: TC=120+180=300; AFC=120/5=24; AVC=180/5=36; ATC=300/5=60; MC=300−248=52.
RUBRIC: 25 = all columns correct (or one minor arithmetic slip that does not cascade), with
Q=3 and Q=5 work shown. 15–20 = mostly right, 2–4 arithmetic errors or one missing column.
8–14 = method right but multiple errors or work not shown. 0–7 = fundamental error (e.g.,
TC=VC only, AFC omitted, MC not computed as ΔTC).
FRESH VARIANT: "Same setup, FC=$120. New VC: Q=1:$50, Q=2:$86, Q=3:$108, Q=4:$134,
Q=5:$170, Q=6:$222. Compute TC, AFC, AVC, ATC, MC for Q=1–6; show work for Q=2 and Q=4."
VETTED FRESH ANSWER:
  Q | VC  | TC  | AFC  | AVC  | ATC  | MC
  1 |  50 | 170 | 120  |  50  | 170  | 50
  2 |  86 | 206 |  60  |  43  | 103  | 36
  3 | 108 | 228 |  40  |  36  |  76  | 22
  4 | 134 | 254 |  30  | 33.5 | 63.5 | 26
  5 | 170 | 290 |  24  |  34  |  58  | 36
  6 | 222 | 342 |  20  |  37  |  57  | 52
  Q=2 work: TC=120+86=206; AFC=120/2=60; AVC=86/2=43; ATC=206/2=103; MC=206−170=36.
  Q=4 work: TC=120+134=254; AFC=120/4=30; AVC=134/4=33.5; ATC=254/4=63.5; MC=254−228=26.

======== PROBLEM 2 (25 pts) — Identify minimum ATC and AVC ========
PROBLEM: "Using the cost table you built in Problem 1 (FC=120):
  (a) At what quantity (Q) is ATC minimized, and what is the minimum ATC?
  (b) At what quantity (Q) is AVC minimized, and what is the minimum AVC?
  (c) Why does the ATC minimum occur at a HIGHER quantity than the AVC minimum?
      (One or two sentences.)"
VETTED ANSWER: (a) ATC is minimized at Q=5: ATC=60. (b) AVC is minimized at Q=3: AVC=30.
  (c) ATC = AVC + AFC. AFC keeps falling as Q rises, so ATC is pulled downward longer than
  AVC is — the falling AFC offsets the rising AVC for a few more units before ATC turns up.
  Therefore ATC minimum always occurs at a higher Q than AVC minimum.
RUBRIC: 25 = both quantities and values correct PLUS a clear one-to-two-sentence explanation
citing falling AFC. 15–20 = both minimums correct, explanation weak. 8–14 = one minimum
correct, explanation missing. 0–7 = both wrong.
FRESH VARIANT (uses fresh P1 table): "(a) At what Q is ATC minimized, and what is min ATC?
  (b) At what Q is AVC minimized? (c) Same explanation question."
FRESH ANSWERS: (a) ATC min at Q=6: ATC=57. (b) AVC min at Q=4: AVC=33.5. (c) Same
reasoning — falling AFC pulls ATC down further.

======== PROBLEM 3 (25 pts) — MC-ATC relationship reasoning ========
PROBLEM: "In the cost table from Problem 1:
  (a) At Q=4, MC=38 and ATC=62. Is ATC rising, falling, or at its minimum at Q=4? Explain
      using the MC-vs-ATC comparison (the 'grade-average' logic), not just by looking at
      the table.
  (b) At Q=5, MC=52 and ATC=60. Is ATC rising, falling, or at its minimum at Q=5? Explain
      the same way.
  (c) In one sentence: what does it mean for a cost schedule when MC equals ATC exactly?"
VETTED ANSWER: (a) At Q=4: MC=38 < ATC=62. When MC is below ATC, the next unit is cheaper
  than average, so adding it pulls the average DOWN. ATC is falling. (b) At Q=5: MC=52 <
  ATC=60. MC is still below ATC, so ATC is still falling. (c) When MC equals ATC exactly,
  ATC is at its minimum — the 'new score equals the old average' means the average neither
  rises nor falls; this is the turn point.
RUBRIC: 25 = both (a) and (b) explain using MC-vs-ATC comparison correctly, PLUS (c) is
  correct. 15–20 = (a) or (b) correct with reasoning; (c) correct. 8–14 = right answers
  but explanation is just "I looked at the table." 0–7 = MC-ATC relationship misunderstood.
FRESH VARIANT: "For the fresh Problem 1 table: (a) Q=3: MC=22, ATC=76 — rising, falling,
  or min? (b) Q=5: MC=36, ATC=58 — rising, falling, or min? (c) Same sentence about
  MC=ATC." FRESH ANSWERS: (a) MC=22<ATC=76 → ATC falling. (b) MC=36<ATC=58 → ATC still
  falling. (c) Same: MC=ATC → ATC at minimum.

======== PROBLEM 4 (25 pts) — Accounting vs. economic profit ========
PROBLEM: "A small graphic-design firm earns total revenue of $480,000 per year. Its
  explicit costs (software licenses, office rent, employee salaries) total $280,000. The
  owner also gave up a salary of $100,000 per year at a design agency to run the firm.
  (a) What is the firm's ACCOUNTING profit?
  (b) What is the firm's ECONOMIC profit?
  (c) The owner says 'My business is profitable — I'm keeping it open.' Is this a rational
      decision from an economics standpoint? Explain in 2–3 sentences, keeping positive and
      normative reasoning separate."
VETTED ANSWER: (a) Accounting profit = TR − explicit costs = $480,000 − $280,000 = $200,000.
  (b) Economic profit = accounting profit − implicit costs = $200,000 − $100,000 = $100,000.
  (c) Yes — economic profit is positive ($100,000), meaning the owner is earning MORE than
  she could in her next-best alternative. Keeping the firm open is rational by the economic
  criterion (positive claim: a positive economic profit means the chosen use beats the
  alternative). A normative claim would be about what she *ought* to value — income, autonomy,
  job satisfaction — but the economics alone supports staying open here.
RUBRIC: 25 = both (a) and (b) correct, AND (c) addresses economic profit sign + separates
  positive from normative. 15–20 = (a) and (b) correct; (c) incomplete. 8–14 = one of
  (a)/(b) right; (c) weak. 0–7 = accounting and economic profit confused.
FRESH VARIANT: "Same firm, but now explicit costs=$360,000 and owner's forgone salary=
  $150,000. (a) Accounting profit? (b) Economic profit? (c) Is staying open rational?"
  FRESH ANSWERS: (a) 480,000−360,000=$120,000. (b) 120,000−150,000=−$30,000 (economic loss).
  (c) No — economic profit is negative: the owner would be $30,000 better off annually at
  the agency. In the long run, an economic loss is a signal to exit (positive claim);
  whether she *should* value the independence of owning a business is normative.

======== COMPLETION ========
After all four problems (and any re-attempts), produce EXACTLY:
    STUDENT'S SCORE: X/100
    WEEK 9 ASSIGNMENT — Production & Costs
    Student: [name] | Date: ___
    Problem 1: a/25 — [one-line note]
    Problem 2: b/25 — [one-line note]
    Problem 3: c/25 — [one-line note]
    Problem 4: d/25 — [one-line note]
    Strongest skill: ___
    Worth another look: ___
Then say, verbatim: "Copy this entire report AND your share link to this chat, and submit
both in Canvas for this assignment." End with one genuine sentence of encouragement.

Instructor grading note + rubric (for Canvas)

Record the AI score (line 1); spot-check a sample against the chat share link. The embedded key makes scores consistent across chatbots. Summary rubric (each problem to 25, total 100):

Quality gate (self-checked): all numbers Python-re-verified — P1 original table: TC(3)=210, ATC(3)=70, MC(3)=22, ATC(5)=60 (min) ✓; AVC(3)=30 (min) ✓. P1 fresh table: TC(4)=254, ATC(6)=57 (min), AVC(4)=33.5 (min) ✓. P4: accounting=200,000; economic=100,000; fresh=120,000/−30,000 ✓. ATC=AVC+AFC verified at every Q in both tables ✓.

Canvas placement block

canvas_object    = Assignment
title            = "Week 9 Assignment — Production & Costs (adaptive)"
assignment_group = "Assignments"
points_possible  = 100
grading_type     = points
submission_types = [online_text_entry, online_url]
due_offset_days  = 6
published        = true
submission_note  = "Paste the AI summary report (score on line 1) + the chat share link."
provenance       = "~ Prof. Kessler's edition · Fall 2026 · built with thecoursemaker.com"

Traditional variant — for comparison. This course is configured adaptive learning, so the actual Week-9 assignment is the AI-coached version in I-assignment-and-rubric-week-09.md. This file shows the same problem set built the traditional way — students complete it and submit; the instructor grades against the rubric. (Choosing assignment_type = traditional at setup generates this style.)

Course: Principles of Microeconomics (ECON 1) · Silver Oak University (fictional sample) · Prof. Kessler
Objective 5 · SLO A & B · Assignment 9 of 14 · 100 points · Due Sun, Nov 1

The Assignment

Show your work and write your interpretations in complete sentences. Submit as a document or text entry.

Problem 1 — Complete a cost table (25 pts). A firm has FC = $120. Its variable costs are: Q=1: $40 · Q=2: $68 · Q=3: $90 · Q=4: $128 · Q=5: $180 · Q=6: $252.

Complete the cost table below by computing TC, AFC, AVC, ATC, and MC for Q = 1 through Q = 6. Show your work for at least Q = 3 and Q = 5.

Problem 2 — Identify minimum ATC and AVC (25 pts).
Using the table you built in Problem 1:
(a) At what quantity (Q) is ATC minimized, and what is the minimum ATC?
(b) At what quantity (Q) is AVC minimized, and what is the minimum AVC?
(c) In one or two sentences, explain why the ATC minimum occurs at a higher quantity than the AVC minimum.

Problem 3 — MC-ATC relationship reasoning (25 pts).
Using the same cost table:
(a) At Q = 4, MC = 38 and ATC = 62. Is ATC rising, falling, or at its minimum at Q = 4? Explain using the MC-vs-ATC comparison (the "grade-average" logic) — not just by reading the table.
(b) At Q = 5, MC = 52 and ATC = 60. Is ATC rising, falling, or at its minimum at Q = 5? Same approach.
(c) In one sentence: what does it mean for a cost schedule when MC equals ATC exactly?

Problem 4 — Accounting vs. economic profit (25 pts).
A small graphic-design firm earns total revenue of $480,000 per year. Explicit costs (software licenses, office rent, employee salaries) total $280,000. The owner also gave up a salary of $100,000 per year at a design agency to run the firm.
(a) What is the firm's accounting profit?
(b) What is the firm's economic profit?
(c) The owner says "My business is profitable — I'm keeping it open." Is this a rational decision from an economics standpoint? Explain in 2–3 sentences, keeping positive ("what the economics says") and normative ("what she ought to value") reasoning separate.

AI note. This is the traditional format — submit your own work. You may use an approved chatbot to check a definition or review a formula, but add a one-line note of which tool and how. (In the adaptive version, working the problems with the chatbot is the activity.)

Grading rubric — 100 points

Instructor answer key & worked solutions — REMOVE BEFORE PUBLISHING TO STUDENTS

P1 — Verified cost table (FC=120):

Q=3 work: TC=120+90=210; AFC=120/3=40; AVC=90/3=30; ATC=210/3=70; MC=210−188=22.
Q=5 work: TC=120+180=300; AFC=120/5=24; AVC=180/5=36; ATC=300/5=60; MC=300−248=52.
(Python-verified: all integer columns confirmed.)

P2: (a) ATC min at Q=5: ATC=60. (b) AVC min at Q=3: AVC=30. (c) ATC=AVC+AFC; since AFC keeps falling as Q rises, it continues to pull ATC down even after AVC begins to rise — so ATC does not turn upward until a higher Q than AVC does. (Verified.)

P3: (a) Q=4: MC=38 < ATC=62 → ATC is falling (a new unit costs less than the current average, pulling it down — same logic as a new test score below your average lowering your average). (b) Q=5: MC=52 < ATC=60 → ATC is still falling (still being pulled down by cheaper marginal cost). (c) When MC equals ATC exactly, ATC is at its minimum — the marginal equals the average, so the average neither rises nor falls. (In this table ATC is minimized uniquely at Q=5 (ATC=60). At Q=5, MC=52 < ATC=60 (still falling); at Q=6, MC=72 > ATC=62 (rising) — so the exact MC=ATC crossing lies between Q=5 and Q=6.)

P4: (a) Accounting profit = $480,000 − $280,000 = $200,000. (b) Economic profit = $200,000 − $100,000 = $100,000. (c) Positive: economic profit is positive, meaning the firm generates more value than the owner's next-best alternative — staying open is rational by the economic criterion. Normative: whether the owner should prioritize income vs. autonomy vs. job satisfaction is a value judgment beyond the positive analysis.

Quality gate (self-checked): all numbers Python-re-verified — P1 table all-integer columns ✓; ATC min Q=5=60 ✓; AVC min Q=3=30 ✓; ATC=AVC+AFC at every Q ✓; P4 arithmetic (200k, 100k) ✓. MC interpretation confirmed (P3: MCATC at Q=6 → rising).

Canvas placement block

canvas_object    = Assignment
title            = "Week 9 Assignment — Production & Costs (traditional)"
assignment_group = "Assignments"
points_possible  = 100
grading_type     = points
submission_types = [online_upload, online_text_entry]
due_offset_days  = 6
rubric_ref       = "w09-assignment-rubric"
published        = true
provenance       = "~ Prof. Kessler's edition · Fall 2026 · built with thecoursemaker.com"