
Jon S. answered 10/24/20
Patient and Knowledgeable Math and English Tutor
Since we don't know the population standard deviation, the test statistic is
t-stat = (M - mu) / (SD/sqrt(n)) = (77.5 - 74.1)/(6.9/sqrt(53) = 3.59
since it is a right tailed test, the p-value is P(t > t-stat) = P(t > 3.59) with n-1 = 52 degrees of freedom = ~ 0.0004.