For a Sample 1000 Twitter Users, Tele-Market Research Reports an Average

Multiple Choice

For a sample 1000 Twitter users, Tele-Market Research reports an average age of 39.If the population standard deviation is 9.5 years, what would be the upper bound for a 90% confidence interval estimate of the mean age of all Twitter users?

A) 35.2
B) 39.5
C) 33.4
D) 41.2
E) 46.1