A 95% confidence interval is constructed in order to estimate the average number of minutes college students spend on Twitter per day. The interval ends up being from 30.1 minutes to 47.1 minutes. Based on this interval, we know the sample mean must be equal to __________________ and the margin of error must be equal to _____________ .

A 95% confidence interval for the proportion of college students who have texted during a class was 0.75 to 0.95. Which of the following is the 90% confidence interval from the same sample? Please choose an answer below and explain the reason for your answer.

A. 0.777 to 0.9

B. 0.05 to 0.25

C. 0.731 to 0.969

D. 0.766 to 0.934

A 90% confidence interval is constructed in order to estimate the average number of hours college students spend studying per week. The resulting interval has a margin of error of 3 hours. Which of the following could be the margin of error for a 95% confidence interval based on the same sample of data? Please choose an answer below and explain the reason for your answer.

A. 8 hours

B. 4 hours

C. 3 hours

D. 2 hours

E. This cannot be answered without knowing the sample size.