An existing inventory for a test measuring self-esteem indicates that the scores have a standard deviation of 12. A psychologist gave the self-esteem test to a random sample of 80 individuals, and their mean score was 65. Construct a 95% confidence interval for the true mean of all test scores. Then give its lower limit and upper limit. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.) Lower limit: II X ? Upper limit