Suppose a random sample of 40 students from a university were asked their ages. The table below gives a summary of the reported ages. Report and interpret a 95% confidence interval for the population mean. Assume the necessary conditions hold.
Age # of students
18 8
19 10
20 9
21 7
22 6
Group of answer choices
(18.0, 22.0). We are 95% confident that the mean age of university students in this sample is between 18 and 22.
(A.19.4, 20.3). We are 95% confident that the mean age of university students in this sample is between 19.4 and 20.3.
(18.0, 22.0). We are 95% confident that the mean age of university students is between 18 and 22.
(19.4, 20.3). We are 95% confident that the mean age of university students is between 19.4 and 20.3.