A multimedia program designed to enhance dietary behavior among low-income women was evaluated through comparing women who were randomly assigned to intervention as well as control groups. The intervention was a 30-minute session in the computer kiosk in the Food Stamp office. One of outcomes was the score on knowledge test taken about two months after the program. Here is a summary of the data:
Group n x s
Intervention 165 5.08 1.15
Control 212 4.33 1.16
Compare the information given by confidence interval with information given by the significance test. A. The two-sided test rejects the null hypothesis at the 5% level of confidence since 0 falls outside confidence interval.
B. The two-sided test does not reject null hypothesis at 5% level of confidence since 0 falls outside the confidence interval.
C. The two-sided test rejects null hypothesis is at the 2.5% level of confidence since 0 falls outside the confidence interval.
D. Confidence intervals are employed for estimating the population mean, not for testing hypotheses.