Inference Procedures

A teacher compares the scores of students in her class on a standardized test with the national average score of 87.3.

• Paired t-test

• 2-sample t-test

• t-test

• 1-prop z-test

A teacher compares the proportion of her students who scored 5’s on the AP exam with the national proportion of 5’s which is 0.124.

• Paired t-test

• 2-sample t-test

• t-test

• 1-prop z-test

A psychology teacher gives students 10 min. to memorize a list of 20 nonsense words. The students are asked to recall the words one hour later and then 24 hours later. Is there evidence to suggest that the mean number of words recalled after 1 hour exceeds the mean recall after 24 hours?

• Paired t-test

• 2-sample t-test

• X² -GOF Test

• t-test

The mean length of long-distance telephone calls placed with a particular phone company was known to be 7.3 minutes under an old rate structure. The company lowered its rates hoping that customers would be encouraged to make longer calls, so there would not be a big loss in revenue. Is

there evidence that lowering the rates was successful?

• Paired t-test

• 2-sample t-test

• X² -GOF Test

• t-test

A researcher wants to know if there is an association between type of exercise (jogging, cycling, swimming, weight lifting) and age among male adults.

• Paired t-test

• 2-sample t-test

• X² -GOF Test

• X² Test

A teacher compares the number of A’s, B’s, C’s, D’s, and F’s in their statistics class to last year.

• Paired t-test

• 2-sample t-test

• X² -GOF Test

• X² Test

Failing to reject a null hypothesis that is false can be characterized as

• a Type I error
• a Type II error
• both a Type I and Type II error
• no error

A Type I error is when: 

• We reject the null hypothesis when it is actually true
• We obtain the wrong test statistic
• We fail to reject the null hypothesis when it's actually false
• We reject the alternate hypothesis when it's actually true

A P-value indicates:

• the probability that the null hypothesis is true
• the probability that the alternative hypothesis is true
• the probability of obtaining the results (or one more extreme) if the null hypothesis is true
• probability of a Type I error

In testing hypotheses, which of the following would be strong evidence against the null hypothesis?

• using a small level of significance
• using a large level of significance
• obtaining data with a small p-value
• obtaining data with a low test statistic