62.PS-11
Question Help
A researcher asked five of his dentist friends if they thought the new Brand X mouthwash that he
developed was effective. Four responded "yes." The researcher used the results to write a TV
advertisement claiming that "4 out of 5 dentists prefer Brand X mouthwash." Is this a valid inference?
Explain
Use pencil and paper. Explain all of the factors that are necessary for an inference to be valid.
Is the inference valid? Explain. Choose the correct answer below.
A. Yes, because the dentists asked are a representative sample of the population of dentists.
OB. No, because the dentists asked are not a representative sample of the population of dentists.
C. Yes, because 4 dentists said yes out of 5 who were asked.
OD. No, because 4 dentists said yes out of 9 who were asked.