A friend tells you that she has conducted a survey to find the proportion of people in her university that utilize the campus internet cafe at least once a day. She has collected a sample and calculated a sample proportion of p = 0.68. She uses this value to calculate a confidence interval for the population proportion. Your friend says that she is not going to tell you the sample size or the level of confidence used in her construction, and wants you to guess what the confidence interval is. She gives you 5 options.

Select the interval(s) that, based on the information given, could possibly be the confidence interval your friend calculated:

a. the interval between 0.68 and 0.88
b. the interval between 0.58 and 0.78
c. the interval between 0.48 and 0.78
d. the interval between 0.58 and 0.88
e. the interval between 0.48 and 0.68