1. In the population of all adults, the proportion who favor legalizing marijuana is 0.56. When a random sample is selected from this population, the proportion in the sample who favor legalizing marijuana is 0.49. We would call the number 0.49 a _________________ and the number 0.56 a _________________.

choose the correct answer

a. statistic; statistic

b. parameter; statistic

c. P-value; z-score

d. parameter; parameter

e. statistic; parameter

2. A sample of students was studied in order to learn more about the relationship between sleeping habits and classroom performance. For each student, the number of hours of sleep they got before a standardized test was recorded, as was the score they received, in points, on the standardized test. Suppose you learn the relationship between hours of sleep and test score is linear, strong, and positive, with r = 0.85. You also learn that a regression equation has been constructed in order to predict test score based on hours of sleep. Given this information, which one of the following statements is correct?

choose the correct answer

a. The units for r should be "points per hour."

b. Because the correlation is strong, we should conclude that how much sleep a student gets causes that student to have a particular test score.

c. It's impossible to know, without more information, if the slope in the regression equation will be positive or negative.

d. The variable "test score" should go on the y-axis when we construct a scatterplot.

e. The explanatory variable is test score and the response variable is hours of sleep.

3. A claim is made that the proportion of all college students who belong to a fraternity or a sorority is 0.08. Believing this claimed value is incorrect, a researcher surveys a random sample of college students and finds the proportion in the sample who belong to a fraternity or a sorority is 0.06. When a hypothesis test is conducted at a significance (or alpha) level of 0.05, the P-value is found to be 0.03. What decision should the researcher make based on the results of the hypothesis test?

Choose the correct answer

a. The null hypothesis should not be rejected.

b. The null hypothesis should be rejected because 0.03 is less than 0.08.

c. The null hypothesis should be rejected because 0.06 is less than 0.08.

d. The null hypothesis should be rejected because 0.05 is less than 0.06.

e. The null hypothesis should be rejected because 0.03 is less than 0.05.

4. According to a recent news story, 75% of all adults subscribe to at least one online video streaming service (e.g., Netflix, Hulu, Britbox, etc.). Suppose we are able to survey a random sample of adults, and we determine the proportion of these adults who subscribe to at least one online video streaming service. We know, if the sampling method is repeated, that the sample proportion will vary from sample to sample. In fact, if we look at the sampling distribution in this case, we will see a distribution that is Normal in shape, with a mean (or center) of 0.75 and a standard deviation of 0.04. From this information, we know the middle 68% of this sampling distribution will be between approximately what two values?

choose the correct answer

a. 0.72 and 0.78

b. 0.71 and 0.79

c. 0.69 and 0.81

d. 0.73 and 0.77

e. 0.66 and 0.84

5. Consider a hypothesis testing situation in which the null hypothesis is p = 0.68 and the alternative is p > 0.68. Data is gathered from a random sample, and calculations yield a value of z = 2.0. Which one of the following conclusions should be drawn based on this information?

choose the correct answer

a. The P-value is smaller than 0.01.

b. There is a 2.0% chance we would observe results at least as extreme as what we observed if the null hypothesis is really true.

c. The P-value is larger than 0.10.

d. The P-value is between 0.05 and 0.10.

e. The P-value is between 0.01 and 0.05.

6. A random sample of breakfast cereals was examined in order to determine if there is a relationship between sugar content in grams and calorie content. When a scatterplot was constructed, the relationship was observed to be linear. The regression equation to predict number of calories based on grams of sugar was as follows: Predicted number of calories = 89.16 + 2.54 (grams of sugar). Which one of the following statements is a correct interpretation of this regression equation?

choose the correct answer

a. As grams of sugar increases by 1, we predict number of calories to increase by 2.54.

b. 89.16% of the variability in number of calories can be explained by the regression equation.

c. The number 2.54 is referred to as an intercept.

d. As number of calories goes up by 2.54, we predict grams of sugar to increase by 1.

e. A cereal with 0 grams of sugar is predicted to have 2.54 calories.

7. Which one of the following statements is true?

Choose the correct answer

a. The probabilities of all possible outcomes of a random phenomenon must sum to 0.9.

b. The "P" in P-value stands for "personal."

c. The probability that an event does not occur is equal to 1 plus the probability that the event does occur.

d. If an outcome never occurs, it will have a probability equal to 0.05.

e. The smaller the P-value, the more evidence we have against the null hypothesis.

8. A national report claims that 85% of American households own at least one television set. A market research analyst questions this claim. Suppose the analyst is able to survey random sample of households in order to test H_o: p = 0.85 against H_a: p 0.85. If the resulting test statistic is z = 2.3, what will the P-value be?

choose the correct answer

a. 1.9786

b. 0.9893

c. 0.0107

d. 0.0214

e. 0.0460

9. A 90% confidence interval is constructed in order to estimate the proportion of adults who have changed jobs in the past six months. The interval ends up between from 0.161 to 0.299. Which of the following could be a 99% confidence interval for the same sample of data?

I. 0.148 to 0.312

II. 0.176 to 0.284

III. 0.128 to 0.292

Choose the correct answer

a. I only

b. More than one of the other answer options could be correct

c. III only

d. II only