AP Statistics - Module 5 Review (Unit 7 in AP Classroom)

The weights (in pounds) of three adult goats are 160, 215, and 195. What is the standard error of the mean for these data?

• 13.13

• 16.07

• 27.84

• 22.73

• 190

We want to construct a one-sample t interval for a population mean using data from a population distribution with unknown shape. In which of the following circumstances would it be inappropriate to construct the interval based on an SRS of size 14 from the population?

• A stemplot of the data is slightly skewed to the left and unimodal.

• A histogram of the data is approximately uniform.

• A boxplot of the data is moderately skewed to the right.

• A dotplot of the data is roughly bell-shaped, except for one high outlier.

• The population consists of 200 individuals.

A significance test was performed to test H₀: μ = 2 versus the alternative H_a: μ ≠ 2. A sample of size 28 produced a standardized test statistic of t = -2.047. Assuming all conditions for inference were met, which of the following intervals contains the P-value for this test?

Which of the following has the smallest probability?

A census Bureau report says that, with 90% confidence, the median income of all U.S. households in a recent year was $70,784 with a margin of error of $605. Which of the following statements is correct?

• 90% of all U.S. households had incomes in the interval $70,784 ± $605.

• We can be sure that the median income for all households in the country lies in the interval $70,784 ± $605.

• 90% of the households in the sample interviewed by the Census Bureau had incomes in the interval $70,784 ± $605.

• The Census Bureau got the result $70,784 ± $605 using a method that will capture the population median household income in 90% of all possible samples.

• 90% of all possible samples of this same size would result in a population median household income that falls with $605 of $70,784.

Anne wants to determine how much better a store-brand fertilizer works as a soil enhancement rather than homemade compost when growing tomatoes. To investigate, she plants two tomato plants in each of five planters. One plant in each planter is grown in soil with store-brand fertilizer; the other plant in grown in soil with homemade compost, with the choice of soil determined at random. In three months, she will harvest and weigh the tomatoes from each plant. Assuming that the conditions for inference are met, which of the following is the correct confidence interval procedure that Anne should use for these data?

• Two-sample z interval for a difference between two population proportions

• Paired z interval for a population mean difference

• Two-sample t interval for a difference between two population means

• Paired t interval for a population mean difference

• Two-sample z interval for a difference between two population means

• Reject H₀ at the α = 0.05 level of significance

• Fail to reject H₀ at the α = 0.05 level of significance

• Reject H₀ at the α = 0.10 level of significance

• Fail to reject H₀ at the α = 0.10 level of significance

• We cannot perform the required test because we do not know the value of the standardized test statistic.

• would be less than 80%.

• would be greater than 80%.

• would still be 80%

• could be either less than or greater than 80%.

• would vary depending on values of μ_T and μ_P.

A 90% confidence interval for the mean μ of a population is computed from a random sample and is found to be 90 ± 30. Which of the following could be the 95% confidence interval based on the same data?

• 90 ± 21

• 90 ± 30

• 90 ± 39

• 90 ± 70

• Without knowing the sample size, any of the other answers could be the 95% confidence interval.