Find the Margin of Error $75.67 < \mu < 80.33$ B) $74.63 < \mu < 81.37$

Multiple Choice

Find the margin of error.
-Thirty randomly selected students took the calculus final. If the sample mean was 78 and the standard deviation was 7.5, construct a 99 percent confidence interval for the mean score of all students.

A) $75.67 < \mu < 80.33$
B) $74.63 < \mu < 81.37$
C) $74.23 < \mu < 81.77$
D) $74.24 < \mu < 81.76$