The brand manager for a brand of toothpaste must plan a campaign designed to increase brand recognition He wants to first determine the percentage of adults who have heard of the brand How many adults must he survey in order to be 90 confident that his estimate is within six percentage points of the true population percentage Complete parts a through c below a Assume that nothing is known about the percentage of adults who have heard of the brand n 188 Round up to the nearest integer b Assume that a recent survey suggests that about 86 of adults have heard of the brand n 90 Round up to the nearest integer c Given that the required sample size is relatively small could he simply survey the adults at the nearest college O A No a sample of students at the nearest college is a cluster sample not a simple random sample so it is very possible that the results would not be representative of the population of adults OB Yes a sample of students at the nearest college is a simple random sample so the results should be representative of the population of adults OC No a sample of students at the nearest college is a stratified sample not a simple random sample so it is very possible that the results would not be representative of the population of adults OD No a sample of students at the nearest college is a convenience sample not a simple random sample so it is very possible that the results would