AP Statistics Choose an Inference Method

Julian wanted to know if he was better at bottle-flipping with his right hand or his left hand. He attempted 100 flips with each hand and counted how many successes he had with each hand.

• A two-sample z-test for the difference of proportions

• A χ2 goodness of fit test

• A paired t-test for the mean difference

• A z-test for a proportion

• A two-sample t-test for the difference of means

The coach of a swimming team wonders if a new swim cap will make their team swim faster than their existing caps. The coach has each swimmer complete two laps—one with the new cap and one with their existing cap (in a random order). They want to test if, on average, the times are lower with the new caps.

• A two-sample t-test for the difference of means

• A t-test for slope

• A two-sample z-test for the difference of proportions

• A χ2 test of independence

• A paired t-test for the mean difference

Finn blogs about video games. In a particular game, a certain enemy occasionally drops a rare item when they are defeated. Finn wants to estimate the likelihood that this enemy drops the rare item, so he defeats the enemy 1000

times and tallies how many times the rare item is dropped.

• A paired t-interval for the mean difference

• A z-test for a proportion

• A t-test for a mean

• A t-interval for a mean

• A z-interval for a proportion

Rex wants to estimate the average finishing time of the approximately 50,000 finishers at the New York City Marathon. He takes a random sample of finishers and records their times.

• A t-test for a mean

• A z-test for a proportion

• A paired t-interval for the mean difference

• A z-interval for a proportion

• A t-interval for a mean

Felipe is curious if there is a relationship between a runner's age and their finishing time in a recent marathon. He takes a random sample of finishers and records the age (in years) and the finishing time (in minutes) for each of those sampled.

• A paired t-test for the mean difference

• A two-sample z-test for the difference of proportions

• A t-test for slope

• A two-sample t-test for the difference of means

• A z-test for a proportion

A market researcher wondered if there was a relationship between a person's age and which media streaming service they preferred. The researcher obtained a random sample of people and categorized each of them as a teen or adult. They also categorized each person based on their preferred streaming service.

• A χ2 goodness of fit test

• A χ2 test for homogeneity

• A two-sample z-test for a proportion

• A χ2 test of independence

• A t-test for slope

Do people pick random numbers uniformly? Kiley asked 100

randomly selected people to pick a random whole number from 1-10 and tallied how often each number was chosen.

• A z-test for a proportion

• A χ2 goodness of fit test

• A χ2 test for homogeneity`

• A χ2 test of independence

• A two-sample z-test for a proportion