Hypothesis Test AP Statistics

Does the data give evidence of an association between gender and soft drink choice?

• Yes, we reject the null hypothesis.

• No, we fail to reject the null hypothesis

• No, we reject the null hypothesis.

• Yes, we fail to reject the null hypothesis.

• Cannot be determined because the large counts condition is not met.

The degrees of freedom for the chi-square test for this two-way table are

• 4

• 8

• 10

• 20

• 4876

Mrs. Trahan claims that her students' average score on the AP exam is 3.9. A random sample of 50 of her students' scores produce a mean score of 3.1 with a standard deviation of 1.5. Does this sample show evidence that Mrs. Trahan is overstating her average score?

• With a test statistic of -3.8 which is unlikely, it seems that Mrs. Trahan may be overstating her average AP score.

• With a test statistic of -4.7 which is unlikely, it seems that Mrs. Trahan may be overstating her average AP score.

• With a test statistic of -0.53 which is not unusual and this sample does not show evidence that Mrs. Trahan is overstating her average AP score.

What test should be used?

• 2 proportion z test

• 1 proportion z test

• 2 sample t test for means

• 1 sample t test for mean

What test should be performed?

• Paired t test

• 1 sample t test for mean difference

• 2 proportion z test

• 2 sample t test for difference in means

What test should be used?

• 2 Sample t test for difference in means

• 2 proportion z test

• Paired t test

• 1 sample z test

A study measures the blood pressure of 50 patients before and after they start taking a new medication. The data are paired and have equal variances. The null hypothesis is that there is no difference in blood pressure before and after the medication, and the alternative hypothesis is that there is a difference. The t-statistic is calculated to be 3.42. What is the p-value?

• A. 0.0036

• B. 0.0012

• C. 0.0024

• D. 0.0008

A car dealership claims that the average gas mileage for a new hybrid car is at least 50 miles per gallon. A sample of 30 new hybrid cars is selected and their gas mileage is measured. The sample mean is 49.2 miles per gallon with a standard deviation of 3.8 miles per gallon. Assuming that the gas mileage is normally distributed, is there sufficient evidence to support the dealership's claim at the 5% significance level?

• Yes, reject the null hypothesis

• No, fail to reject the null hypothesis

A study measures the IQ scores of 20 identical twins and 20 fraternal twins. The mean IQ score for the identical twins is 115 with a standard deviation of 10, and the mean IQ score for the fraternal twins is 110 with a standard deviation of 12. Is there sufficient evidence to support the claim that identical twins have a higher mean IQ score than fraternal twins at the 1% significance level?

• Yes, reject the null hypothesis

• No, fail to reject the null hypothesis