Researchers hypothesized that school-aged children under stress give what they perceive to be more socially desirable answers on an angst measure than normal children do, resulting in lower angst scores. For the data on the 36 children under stress the mean angst score was 11.00, with a standard deviation of 6.99. The population mean angst score for school-aged children on this measure is reported as 15.45. Do the stressed children report significantly lower levels of angst than children in the general population?