Rachel purchased different carpets that had the same ratio of the length to the width. the table below shows the length and width of some carpets rachel bought: length (feet) width (feet) 4 3 8 6 12 9 16 12 ? 15 the missing value in the table is feet.

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