1. The effect of a new behavioral therapy on depression (as measured by the Beck

Depression Inventory) is being investigated. How might an experimenter

demonstrate that, on average, the reduction in Beck Depression Inventory scores

is 20 points or more?

2. Heights for 14-year-old boys and girls were calculated. The mean height for

the sample of 12 boys was 174 cm with s2= 62. For the sample of 12 girls, the

mean was 166 cm with s2= 65. Construct the 95% confidence intervals for the

population mean height for boys and for girls. (Two separate confidence

intervals.)