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Name That Scenario :Inferential Statistical Analysis with Python (Statistics with Python Specialization) Answers 2025

  1. Question 1 — Blind taste test to estimate percentage who prefer grape
    ❌ Single population proportion
    ❌ Difference in two population proportions
    ❌ Single population mean
    ❌ Population mean difference for paired data
    ✅ Difference in two population proportions

Explanation: Two flavors (grape vs apple) compared within consumers to estimate the proportion preferring grape relative to apple — this is a comparison between two proportions (preference counts for grape vs apple).

  1. Question 2 — Job satisfaction measured before and after for the same 30 workers
    ❌ Single population proportion
    ❌ Difference in two population proportions
    ❌ Single population mean
    ✅ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: The same workers are measured before and after, so observations are paired (pre/post). We analyze the mean difference within pairs.

  1. Question 3 — Compare participation rate today vs ten years ago using two independent samples (alumni and current students)
    ❌ Single population proportion
    ✅ Difference in two population proportions
    ❌ Single population mean
    ❌ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: Two independent groups (alumni vs current students) with binary outcome (participates or not) → compare two proportions.

  1. Question 4 — Estimate difference in average wait times for donors with appointment vs without
    ❌ Single population proportion
    ❌ Difference in two population proportions
    ❌ Single population mean
    ❌ Population mean difference for paired data
    ✅ Difference in two population means

Explanation: Two independent groups (appointment vs no appointment) and the outcome is a quantitative variable (wait time) → compare two means.

  1. Question 5 — Compare rate of skiers vs snowboarders who know the Responsibility Code
    ❌ Single population proportion
    ✅ Difference in two population proportions
    ❌ Single population mean
    ❌ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: Two independent groups (skiers vs snowboarders) and the outcome is binary (can/cannot state code) → compare two proportions.

  1. Question 6 — Estimate percentage of all cars on the road that may be unsafe from random stops
    ✅ Single population proportion
    ❌ Difference in two population proportions
    ❌ Single population mean
    ❌ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: One population (all cars) with a binary outcome (unsafe or not) → estimate a single population proportion.

  1. Question 7 — Test if average trip time in Ann Arbor is less than known average 12.8 minutes
    ❌ Single population proportion
    ❌ Difference in two population proportions
    ✅ Single population mean
    ❌ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: Compare the mean trip time in one population (Ann Arbor scooters) to a known population mean → one-sample mean scenario.

  1. Question 8 — Two treatments A and B with cured counts out of separate samples
    ❌ Single population proportion
    ✅ Difference in two population proportions
    ❌ Single population mean
    ❌ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: Two independent samples with binary outcome (cured or not) → compare two proportions (healing rates).

  1. Question 9 — Heart rate recorded before class and midway for each participant
    ❌ Single population proportion
    ❌ Difference in two population proportions
    ❌ Single population mean
    ✅ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: Measurements on the same participants at two times (before and during) → paired differences in heart rate (mean difference).

  1. Question 10 — Compare new checkout times (n=35) to historical average of 6 minutes
    ❌ Single population proportion
    ❌ Difference in two population proportions
    ✅ Single population mean
    ❌ Population mean difference for paired data
    ❌ Difference in two population means

Explanation: One sample of checkout times compared to a known historical mean → one-sample mean inference.

🧾 Summary Table

Q # Correct scenario (short) Key concept
1 Difference in two population proportions Compare preferences between two categories (grape vs apple) → two proportions
2 Paired mean difference Same subjects measured before & after → paired test
3 Difference in two population proportions Two independent groups, binary outcome → two-proportion comparison
4 Difference in two population means Two independent groups, quantitative outcome → two-mean comparison
5 Difference in two population proportions Two independent groups, binary outcome → two-proportion comparison
6 Single population proportion One population, binary outcome → estimate a proportion
7 Single population mean One sample compared to known mean → one-sample mean test
8 Difference in two population proportions Two treatment groups, binary outcome → compare proportions
9 Paired mean difference Repeated measures on same people → paired mean difference
10 Single population mean One sample compared to historical mean → one-sample mean test