1. Calculate the 95% CI's of total caloric intake separately for the cases and controls. What can be concluded about the statistical similarities of the two population means? (3 points)
2. Calculate the 95% CI of the difference of total caloric intake means between cases and controls. Provide an interpretation of the results. What can be concluded from this? (3 points)
3. Use an appropriate test to determine whether there is a significant difference in total caloric intake between cases and controls. Be sure to clearly state your hypotheses, test statistic, and appropriate conclusions. (3 points)
4. Pretend that cases act as their own control in this study (ie data were collected prior to colorectal cancer was diagnosed and then after diagnosis). What type of test would you conduct to determine if total caloric intake was different between cases and controls? How would this test differ from your previously conducted test? (2 points)

Table 1. General characteristics of the study subjects 1. Controls (n = 1846) Cases (n = 923) p-Value Age (years) 56.1 + 9.1 56.6 +9.7 0.20 FeMale 596 (32.3) 298 (32.3) >0.99 Family history of colorectal cancer 99 (5.4) 99 (10.7) 25 620 (33.6) 283 (30.7) Educational level Middle school or less 282 (15.6) 321 (34.8) 400 545 (32.3) 215 (23.3) Marital Status Married 1654 (90.4) 773 (83.8)