Compute the 95% confidence limits on mean anxiety for the data in Exercise 12.19.

Exercise 12.19

In Section 12.3 we ran a t test to test the hypothesis that young children under stress give what they perceive to be more socially desirable answers on an anxiety measure than normal children do. We never really tested the hypothesis that they report lower levels of anxiety.

For the data on these 36 children the mean anxiety score was 11.00, with a standard deviation of 6.085. The population mean anxiety score for elementary school-aged children on this measure is reported as 14.55. Do our children show significantly lower levels of anxiety than children in the general population?