A Random Sample of 250 Students at a University Finds $15.4$

Multiple Choice

A random sample of 250 students at a university finds that these students take a mean of $15.4$ credit hours per quarter with a standard deviation of $1.7$ credit hours. The $90 \%$ confidence interval for the mean is $15.4 \pm 0.177$ . Interpret the interval.

A) We are $90 \%$ confident that the average number of credit hours per quarter of students at the university falls in the interval $15.223$ to $15.577$ hours.
B) The probability that a student takes $15.223$ to $15.577$ credit hours in a quarter is $0.90$ .
C) We are $90 \%$ confident that the average number of credit hours per quarter of the sampled students falls in the interval $15.223$ to $15.577$ hours.
D) $90 \%$ of the students take between $15.223$ to $15.577$ credit hours per quarter.