A college admissions officer takes a simple random sample of

A college admissions officer takes a simple random sample of 100 entering freshmen and computes their mean mathematics SAT score to be 481. Assume the population standard deviation is 121. What is the lower bound of the 99% confidence interval?

Round your answer to the nearest integer. Write only a number as your answer.

Solution

Random sample size =100

Mean =481

sigma =121

99% confidence interval

z score = 2.58

Hence confidence interval lower bound = Mean - 2.58sigma

=449.83