A researcher asked five of his doctor friends if they thought the new Brand X medicine that he developed was effective. Four responded "yes." The researcher used the results to write a TV
advertisement claiming that "4 out of 5 doctors prefer Brand X medicine." 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.
OA. No, because the doctors asked are not a representative sample of the population of doctors.
OB. No, because 4 doctors said yes out of 9 who were asked.
OC. Yes, because 4 doctors said yes out of 5 who were asked.
OD. Yes, because the doctors asked are a representative sample of the population of doctors.