A Student Looked Up the Number of Years Served by 35

Multiple Choice

A student looked up the number of years served by 35 of the more than 100 Supreme Court justices. The average number of years served by those 35 justices was 13.8. If the
Standard deviation of the entire population is 7.3 years, find the 95% confidence interval
For the average number of years served by all Supreme Court justices.

A) $12.2 < \mu < 15.4$
B) $11.8 < \mu < 15.8$
C) $12.6 < \mu < 15.0$
D) $11.4 < \mu < 16.2$