3. Specify the confidence interval criteria. a. Check the assumptions. The samples of size 20 for each group come from normally distributed parent populations and the for each group are unknown. b. Determine the test statistic to be used to The test statistic is the t, using $1 = calculate the interval. and $2 c. State the level of confidence. For a 95% confidence, @= 1-0.95 =0.05 From the t-table, with a df = 19 for each group, the confidence coefficients are for each group. 4. Collect and present sample evidence. a. Collect the sample information. The sample information consists of 20 raw scores for each group. From the experimental group: n= 20, so df = 19 X =82.5, and s = From the control group: n=20, so df =19 X =80, and s = b. Find the point estimate. The point estimates for the population means are the sample means. Thus, the point estimate for P1 is 82.5 and the point estimate for 2 is 80. b.95% Confidence Interval 5. Determine the confidence interval. a. Determine the confidence coefficient. Since n=20, then the df=19. The confidence coefficients in the t-Table under 0.95 (for 95%) is