An existing inventory for a test measuring self-esteem indicates that the scores have a standard deviation of 10. A psychologist gave the self-esteem test to a random sample of 60 individuals, and their mean score was 68. Construct a 90% condence 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: D Upper limit: D