Quiz — Lecture 28

Section A from memory, one line each. Section B shows your reasoning - marks are for method, not final answers. Answers are discussed in class; the exit ticket goes on a card.

Section A

A1. When do mean and median diverge, and which survives?

A2. Churn 10% -> 8%: both units.

A3. Price +20% then -20%: final and why.

A4. Name three parts of an honest summary.

Section B

B1. Salaries 30, 32, 35, 38, 200 (k): mean, median, and the alarm.

B2. Waiting times: median 3, mean 18.5, 25% over 30 min - which single number misleads, and how?

Exit ticket

Answer one of these on your card in 60 seconds (choose any one):

1. When must the median replace the mean?

1. What is the percentage maze's core error?

1. State the inspection paradox in one line.

Homework

• Before: skim the four student pages; attempt case 1 on paper.
• After: write a five-line pseudocode solution for any case you did not
• Enrichment (optional): the stretch question on each case page.