Inference for Categorical Data: Proportions unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Paper 1 Paper 2 Paper 3

Each paper is built from this unit’s 59 terms and is the same for everyone, so a teacher can assign “Unit 3, Paper 2” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.

Suggested time 32 min 29 points0/17 attempted

Chi-square statistic

Margin of error

Interpreting a confidence interval

p-value definition

Degrees of freedom, two-way tables

One-sided vs two-sided alternatives

Expected count formula

Interpreting a p-value in context

Pooled proportion

Choosing the alternative

Interpreting a large contribution to chi-square

Point estimate

Short answer 1. Define or explain: Effect size and power

3 pts

Short answer 2. Define or explain: Calculating expected counts

3 pts

Short answer 3. Define or explain: Follow-up after a significant chi-square

3 pts

Short answer 4. Define or explain: Using a confidence interval to test

3 pts

Free response

5 pts

A city council wants to know whether support for a proposed transit levy differs between two neighborhoods. In an independent random sample of 400 residents of Neighborhood A, 210 said they support the levy. In an independent random sample of 350 residents of Neighborhood B, 168 said they support the levy.

A. State the appropriate hypotheses for a test of whether the proportions of supporters differ in the two neighborhoods.

B. Verify that the conditions for the test are met.

C. Calculate the value of the test statistic and the p-value.

D. At the α = 0.05 level, state your conclusion in the context of the study.