Use the Margin of Error, Confidence Level, and Standard Deviation $25.4$

Multiple Choice

Use the margin of error, confidence level, and standard deviation ? to find the minimum sample size required to estimate an unknown population mean µ
-A group of 51 randomly selected students have a mean score of $25.4$ with a standard deviation of $3.1$ on a placement test. What is the 90 percent confidence interval for the mean score, $\mu$ , of all students taking the test?

A) $24.3 < \mu < 26.5$
B) $24.4 < \mu < 26.4$
C) $24.7 < \mu < 26.1$
D) $24.5 < \mu < 26.3$