3 Among the factors involved in building a confidence interval are: the sample size n, the level of confi and the margin of error. Which of the following statements are true? a For a specified confidence level, larger samples provide smaller margins of error. b For a given confidence level, a sample 16 times as large will make a margin of error one-fourth as big C For a given sample size, a higher confidence level means a smaller margin of error. Both a and b are true. e Both b and c are true