A simple random sample of 50 adults were surveyed, and it was found that the mean amount of time that they spend surfing the Internet per day is 54.2 minutes, with a standard deviation of 14.0 minutes. What is the 99% confidence interval for the number of minutes that an adult spends surfing the Internet per day?

49.1 minutes to 59.3 minutes
50.3 minutes to 58.1 minutes
54.2 minutes to 58.1 minutes
54.2 minutes to 59.3 minutes

Question

A simple random sample of 50 adults were surveyed, and it was found that the mean amount of time that they spend surfing the Internet per day is 54.2 minutes, with a standard deviation of 14.0 minutes. What is the 99% confidence interval for the number of minutes that an adult spends surfing the Internet per day? 

49.1 minutes to 59.3 minutes
50.3 minutes to 58.1 minutes
54.2 minutes to 58.1 minutes
54.2 minutes to 59.3 minutes

kropot72 · Answer

Do you know the formula for calculating the confidence interval?

anonymous · Answer

@pitamar Do you think you could help me out with this one as well? D: I'm helpless here. Lol.

anonymous · Answer

@iGreen