Question

select the correct answer from each drop-down menu.

a dentist conducts a survey to determine whether a certain brand of mouthwash improves gum health more than others. when his patients come in for their regular cleanings, the dentist surveys them about their mouthwash use and makes a conclusion based on the survey results.

the conclusion drawn from the study is choose an answer because the sample is choose an answer. in this instance, an choose an answer study was conducted.

Explanation:

Identify the study type

The dentist asks patients about their existing mouthwash habits without assigning treatments. This is an observational study.

Evaluate sample bias

The sample consists only of the dentist's own patients who come in for regular cleanings. This is a convenience sample and is biased (not representative of the general population).

Determine validity of conclusion

Because the sample is biased and the study is observational (which cannot establish direct cause-and-effect), the conclusion drawn from the study is invalid.

Answer:

Select the correct answer from each drop-down menu.

A dentist conducts a survey to determine whether a certain brand of mouthwash improves gum health more than others. When his patients come in for their regular cleanings, the dentist surveys them about their mouthwash use and makes a conclusion based on the survey results.

The conclusion drawn from the study is <blank>invalid</blank> because the sample is <blank>biased</blank>. In this instance, an <blank>observational</blank> study was conducted.