Lemma
MediumChi-square tests
OpenStax, Introductory Statistics 2e §11.6 Test of a Single Variance · Exercise 24 · Statistics · Chi-square tests

Test of a Single Variance · Exercise 24

For each word problem, use a solution sheet to solve the hypothesis test problem. Go to for the chi-square solution sheet. Round expected frequency to two decimal places.

Consumers may be interested in whether the cost of a particular calculator varies from store to store. Based on surveying 43 stores, which yielded a sample mean of $84 and a sample standard deviation of $12, test the claim that the standard deviation is greater than $15.

This is an open-ended exercise: its source gives no single answer.

~8 minWritten answer · check your work with Lemma

OpenStax, Introductory Statistics 2e · §11.6 Test of a Single Variance · Exercise 24

Stuck? A gentle nudge

No hints for this one.

Something off?
Workspace
Your working

Check your full solution

Attach photos of your pages (up to 3) or one PDF — or check what you typed above. Lemma reads the work and verifies the reasoning, not just the answer.

Your first check today doesn't need an account.

Your photos and PDFs are read once and not stored — only the transcription is kept.