Faculty Members at a Local University Complain That Achieving Tenure

Multiple Choice

Faculty members at a local university complain that achieving tenure at their university takes much longer than at comparable universities.They randomly sample nine tenured faculty members at their university and find that the average time of service prior to tenure was 13.55 years, with a standard deviation of 1.98 years.What is a 95% confidence interval for the mean number of years of service to achieve tenure at this university?

A) (12.028, 15.072)
B) (12.057, 15.043)
C) (12.256, 14.844)
D) (8.984, 18.116)