1. Greta and Greg are twins. Their parents want to know if watching television helps or harms language development. They design a long-term experiment in which Greta watches twice as much television as Greg every day. Which statement is true of this experiment?

a. The amount of television that each twin watches is the response variable.

b. The twin's language development and the amount of television that each twin watches are both explanatory variables.

c. The twins' language development is the response variable.

d. The twins' language development is the explanatory variable.

2. A group of elementary school students designed a study to find a possible relationship between the number of students absent from school and the overall rate of flu infections in their town. Which of the following is a correct pairing of possible null and alternative hypotheses for this experiment?

a. The null hypothesis is that the flu infection rate has no impact on the number of students absent from school. The alternative hypothesis is that as the flu infection rate increases, the number of students absent from school also increases.

b. The null hypothesis is that as the flu infection rate decreases, the number of students absent from school also decreases. The alternative hypothesis is that as the flu infection rate increases, the number of students absent from school increases.

c. The null hypothesis is that the flu infection rate has no impact on the number of students absent from school. The alternative hypothesis is that as the flu infection rate increases, the number of students absent from school remains the same.

d. The null hypothesis is that as the flu infection rate decreases, the number of students absent from school also decreases. The alternative hypothesis is that as the flu infection rate increases, the number of students absent from school remains the same.

3. Lori puts up a sign for her business 500 meters from the main entrance. She once read that it takes the average adult 6 minutes to walk 500 meters. She decides to test this by having 200 adults walk the 500 meters from her sign to her store. Which of the following is the sample in Lori's experiment?

a. All adults

b. The 200 adults

c. The average of 6 minutes

d. The 500 meters

4. Which example demonstrates participation bias?

a. A doctor's office conducts a quality review of their medical charts by randomly reviewing every third chart.

b. A clothing store collects surveys from every customer whose order totals more than $100.

c. A study that only tested one type of insect concludes that a certain pesticide is more effective for defending tomato plants against all pests.

d. A study concludes that adults generally prefer whole milk over skim milk, based on voluntarily submitted data.

5. After a set of surveys was compiled and analyzed, the mean value was reported as 5.1 0.4. Select the true statement for this data.

a. The estimate is equal to 0.4 and the confidence interval is 4.7 to 5.5.

b. The margin of error is equal to 0.4 and the confidence interval is 5.1.

c. The margin of error is equal to 5.1 and the estimate is equal to 0.4.

d. The estimate is equal to 5.1 and the confidence interval is 4.7 to 5.5.