In our class, you are all very good at solving confidence interval formulas. That said, it is important to know what the confidence interval components are. Based on your experience solving confidence interval problems in the course, the critical value used in a 95% confidence interval for a population proportion can be best described as:

a)The average variability of the sample proportion in all samples of size n from the population

b)The value in a standard Normal distribution such that 95% of the scores are above that value

c)The value in a t-distribution such that 95% of the scores are above that value

d)The product of a value calculated from the standard Normal distribution for 95% and the standard error of the sample proportion

e)None of these answers

f)The value in a standard Normal distribution such that 95% of the scores are less than that distance from 0