Question
A group of 56 randomly selected students have a mean score of 30.8 and a
standard deviation of 4.5 on a placement test. Find a 95% confidence interval
for the mean score, ì, of all students taking the test. (Note: ó is unknown.)
standard deviation of 4.5 on a placement test. Find a 95% confidence interval
for the mean score, ì, of all students taking the test. (Note: ó is unknown.)