A newly developed composite dental filling material is hypothesized to reduce the occurrence of cold sensitivity of a restored tooth (e.g., a tooth with a cavity that has been treated with a dental filling material). Forty subjects each had two cavities that needed to be treated and each received two fillings. One tooth was restored with the new filling material and one tooth was restored with a leading brand of composite dental filling material. After 3 months, each tooth was sprayed with very cold water, and subjects rated whether they felt any or no sensitivity (yes or no) for each tooth.

1. What is the data type of the outcome(s) variable in this study? (There may be more than one correct answer.)

A. Categorical - nominal

B. Categorical - ordinal

C. Quantitative - discrete

D. Quantitative - continuous

2. Which scenario below best describes the study design?

A. One group with one outcome (or variable of interest).

B. Two dependent or paired groups with one outcome (or variable of interest).

C. Two independent groups with one outcome (or variable of interest).

D. One group with two outcomes (or two variables of interest).

3. State an appropriate scientific hypothesis.

4. State in words an appropriate null and alternative hypothesis