1. Consider what you know about the sampling distribution of the sample proportion. This sampling distribution

Choose the correct answer

a. will be Normal in shape only if the sample size is at least 100.

b. will become more variable as the sample size increases.

c. is a collection of the statistics of all possible samples of a particular size taken from a particular population.

d. will have a center equal to 0.50.

e. has a shape that is skewed to the right, regardless of sample size.

2. Which one of the following statements about confidence intervals is true?

Choose the correct answer

a. When constructing a confidence interval, the value added to and subtracted from the sample statistic is called the parameter.

b. The width of a confidence interval is determined by the size of the sample.

c. Confidence intervals are constructed with the goal of estimating an unknown sample statistic.

d. As long as the sample is random, the confidence interval will definitely include the population parameter.

e. The population parameter is always right in the center of the confidence interval.

3. The relationship between the number of square feet and the selling price (in dollars) of a sample of homes for sale in Cincinnati, Ohio, is observed to be linear, with a correlation of r = 0.58. A regression equation is subsequently constructed in order to predict selling price based on number of square feet. What percentage of the variability in selling price can be explained by this regression equation?

Choose the correct answer

a. It is impossible to answer this question without seeing the regression equation.

b. 58.00%

c. 76.16%

d. 29.00%

e. 33.64%

4. A researcher interviews members of thousands of households in order to learn more about family size. In particular, the researcher is trying to learn about the number of children that different families have. The following probability model gives the probabilities associated with having different numbers of children in a family. Based on this model, what is the probability of choosing a family at random and finding that this family has at most 2 children?

Number of children	0	1	2	3	4	5	6	7	8 or more
Probability	0.27	0.16	0.25	0.15	0.08	0.04	0.02	0.01	0.02

choose the correct answer

a. 0.68

b. 0.25

c. 0.57

d. 0.41

e. 0.32

5. You want to estimate the proportion of residents in your community who have landline telephones. You survey a random sample of 480 residents and find that the proportion who have landline telephones is 0.55. If you want to construct a 99% confidence interval, what will the margin of error be? As you engage in your calculations, do not do a lot of rounding until you near the end of your calculations, and choose the answer below that is closest to your final result.

choose the correct answer

a. 0.036

b. 0.001 or smaller

c. 0.010

d. 0.023

e. 0.059

6. It is claimed that 23% of college students pay for their education with a student loan. Believing this claimed value is too high, a researcher surveys a random sample of college students and finds that 20% are paying for their education with a student loan. When a hypothesis test is conducted, the researcher writes out her alternative hypothesis as "p = 0.20." What is wrong with this alternative hypothesis?

Choose the correct answer

a. The alternative hypothesis should be "p > 0.23."

b. The alternative hypothesis should be "p > 0.20."

c. The alternative hypothesis should be "p < 0.20."

d. The alternative hypothesis should be "p < 0.23"

e. Nothing is wrong.

7. A 95% confidence interval is constructed in order to estimate the proportion of adults who regularly use a microwave oven to prepare their meals.The interval ends up being from 0.414 to 0.486. What should we conclude based on this information?

choose the correct answer

a. The margin of error is equal to 0.05.

b. If the confidence level had been 90% instead of 95%, the confidence interval would have been wider.

c. The true population proportion may or may not be between 0.414 to 0.486.

d. The sample proportion is 0.43.

e. 95% of adults use a microwave oven to prepare their meals between 41.4% and 48.6% of the time.

8. Which one of the following statements is correct?

Choose the correct answer

a. A correlation of r = 1.75 means there is a very strong relationship between two quantitative variables.

b. A correlation of r = 0.7 is stronger than a correlation of r = -0.7.

c. If a correlation coefficient is negative, this means that as values of one variable go down, values of the other variable also tend to go down.

d. The presence of an outlier can have an impact on the correlation between two quantitative variables.

e. It's possible for the value of r-squared to be negative.

9. It is reported that the proportion of all college students who live on campus is p = 0.62. If we take many random samples of size n = 825 college students from this population, we know the sample proportion who live on campus will vary. We also know the sampling distribution in this case will have a standard deviation equal to approximately what value?

choose the correct answer

a. 0.0212

b. 0.0310

c. 0.2356

d. 0.0169

e. 0.0254

10. Blane and Andie are each attempting to estimate the proportion of high school seniors who attend the senior prom. Blane selects a large random sample of high school seniors to survey, and he observes a sample proportion of 0.52. Andie selects a different large random sample of high school seniors to survey, and she also observes a sample proportion of 0.52. Blane and Andie each use their sample data to construct a confidence interval. Blane's interval is from 0.458 to 0.582, and Andie's interval is from 0.438 to 0.562. One of these intervals was computed correctly, but the other was not. Which interval must be incorrect?

choose the correct answer

a. Andie's interval must be incorrect.

b. It's impossible to answer this question without knowing the sample sizes.

c. It's impossible to answer this question without knowing the sample sizes or the level of confidence used for each interval.

d. It's impossible to answer this question without knowing the level of confidence used for each interval.

e. Blane's interval must be incorrect.