Over a period of years, a study finds a negative correlation between the amount of natural gas (in "therms") consumed in a given week and the sales of ice cream.

1. Draw a picture of a scatterplot that could represent this relationship. Label both axes.

2. Which of the following best describes your scatterplot?

a. Points with higher x-values tend to have higher y-values, and points with lower x-values tend to have lower y-values.

b. Points with higher x-values tend to have lower y-values, and points with lower x-values tend to have higher y-values.

c. The points in the scatterplot do not display a pattern.

3. This data is from an:

a. Observational study

b. Experiment

4. The cases for this study are:

a. People who eat ice cream

b. Weeks

c. Natural gas stores

d. Ice cream stores

5. The explanatory variable is:

a. Which week it is

b. Sales of ice cream

c. Amount of natural gas consumed

6. with unit of:

a. Weeks

b. Dollars

c. Therms

7. and the response variable is:

a. Sales of ice cream

b. Which week it is

c. Amount of natural gas consumed

8. with units of:

a. Weeks

b. Therms

c. Dollars

9. Both variables are:

a. Quantitative

b. Categorical

10. If a hypothesis test determines that the relationship is significant, can we conclude that decreasing natural gas consumption will cause an increase in ice cream sales?

a. No, decreasing natural gas consumption will cause a decrease in ice cream sales.

b. Yes, since ice cream sales are the response variable a decrease in natural gas consumption will cause an increase in ice cream sales.

c. No, it could be that both variables are responding to a third variable, in which case decreasing natural gas consumption will have no effect on ice cream sales.

11. Which of the following variables is most likely to contribute to both natural gas consumption and ice cream sales?

a. Price of ice cream

b. Price of natural gas

c. TemperatureNone of the above