An orthodontist compares cement bond strength in 40 patients who do not drink soda and 40 who do drink soda.

An orthodontist compares cement bond strength in 40 patients who do not drink soda and 40 who do drink soda.

• A. 3-Sample ANOVA
• B. 2-Sample T-Test
• C. Paired T-Test
• D. 1-Sample T-Test

Answer: (B)

This question tests comparing means between two independent groups. The orthodontist is looking at cement bond strength for patients who do not drink soda versus those who do, with 40 in each group. Since the two groups are independent and you want to know if their average bond strengths differ, the appropriate analysis is a two-sample t-test. It evaluates whether the observed difference in means could occur if the true means were actually equal, accounting for variability and sample sizes. The other choices don’t fit: a paired t-test is for related or matched measurements on the same subjects, a one-sample t-test compares a single group to a known value, and an ANOVA is used when there are three or more groups.

This question tests comparing means between two independent groups. The orthodontist is looking at cement bond strength for patients who do not drink soda versus those who do, with 40 in each group. Since the two groups are independent and you want to know if their average bond strengths differ, the appropriate analysis is a two-sample t-test. It evaluates whether the observed difference in means could occur if the true means were actually equal, accounting for variability and sample sizes. The other choices don’t fit: a paired t-test is for related or matched measurements on the same subjects, a one-sample t-test compares a single group to a known value, and an ANOVA is used when there are three or more groups.