Jay, Kip, and Tia are each measuring the concentration of a solution. They are doing experiments separately. They are all are using a colorimeter—a device used for measuring colors. Jay repeats the experiment five times and takes the average measurement, while Kip performs the experiment once. Tia repeats the experiment three times but chooses one of the measurements instead of the average.

Researchers are conducting experiments to determine the role of alcohol in the development of depression. after the study is complete, they determine that the relative risk of developing depression is 1.55 with a 95 % ci of 1.2 -1.9. each group is then divided into nonsmokers and smokers. the relative risk for the nonsmokers is 1.12 with a 95% ci of 0.87-1.37. the relative risk for the smokers is 1.7 with a 95 % cl of 1.5-1.9. what type of bias may affect this study? a. procedure bias b. recall bias c. selection bias d. confounding e. lead-time bias