Dr. Benner an industry psychologist. She is currently studying stress among executives of internet companies. She has developed a questionnaire that that measures stress. A score above 80 indicates stress at a dangerous level. A random sample of 15 executives reveled the following, 94, 78, 83, 90, 78, 99, 97, 90, 97, 90, 93, 94, 100, 75, 84, construct a 95% confidence level of the population mean?