A consumer testing service tested whether the average baking time of whole wheat bread in gas ovens was less than the average baking time of whole wheat bread in electric ovens. Ten loaves of whole wheat bread were prepared, and five were randomly assigned to be baked in five randomly selected gas ovens, while the other five were randomly assigned to be baked in five randomly selected electric ovens.

1. What is the explanatory variable, and is it quantitative or categorical?

A. Type of oven (gas versus electric), which is categorical
B. Baking time, which is quantitative
C. Baking time, which is categorical
D. Type of oven (gas versus electric), which is quantitative
E. Type of bread, which is categorical
F. Type of bread, which is quantitative

2. What is the response variable in this scenario, and is it quantitative or categorical?

A. Baking time, which is quantitative
B. Type of bread, which is categorical
C. Type of oven (gas versus electric), which is quantitative
D. Baking time, which is categorical
E. Type of oven (gas versus electric), which is categorical
F. Type of bread, which is quantitative

3. Which procedure should be used for this test?

A. Chi-square test
B. Analysis of variance
C. Two-sample z-test for proportions
D. One-sample z-test for proportion
E. Regression analysis
F. Two-sample t-test for means
G. Matched pairs t-test for mean difference
H. One-sample t-test for mean (but not matched pairs)

An explanatory variable is an independent variable that is not affected by all other variables. In this experiment, the type of oven is the input variable and it is not affected by any other variable

A categorical variable is one that has two or more categories without any intrinsic ordering of the categories. The type of oven is either gas or electric, so it is categorical.

A response variable is a dependent variable whose variation depends on other variables. The baking time in this experiment depends on the type of oven used

A quantitative variable is one that take on numerical values.

A two proportion z-test allows you to compare two proportions to see if they are the same. The null hypothesis (H0) for the test is that the proportions are the same. The alternate hypothesis (H1) is that the proportions are not the same.