Sachiko is framing the border of a square picture. If she knows the area of the picture, how could Sachiko determine the amount of framing material she needs to buy?
A. Divide the area by 2, and then multiply the quotient by 4.
B. Set the area equal to x2, solve for x, and then multiply the value of x by 4.
C. Set the area equal to x3, and then solve for x.
D. Set the area equal to x2, solve for x, and then divide the value of x by 4.

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