Question

Which of the following statements are true?

Note that there may be more than one correct answer; select all that are true.

		In order for the inference procedures for proportions to be valid, the population from which the random sample is drawn must be normally distributed.
		As the desired margin of error decreases, then the required minimum sample size will increase.
		When determining the minimum sample size, if the value of p^ is not given, we should use the "worst-case scenario" value of p^ = 0.1.
		The formula for standard error of the sample proportion differs between confidence intervals and hypothesis testing, in that for confidence intervals we use p^and(1−p^), and in hypothesis testing we use p0and(1−p0).
		Generally speaking, the confidence interval procedures are valid if n⋅p^andn⋅(1−p^) are both greater than or equal to 15.

Answer 1

Ans:

As the desired margin of error decreases, then the required minimum sample size will increase.

In order for the inference procedures for proportions to be valid, the population from which the random sample is drawn must be normally distributed.

The formula for standard error of the sample proportion differs between confidence intervals and hypothesis testing, in that for confidence intervals we use p^and(1−p^), and in hypothesis testing we use p0and(1−p0).