The graph makes it appear that there are how many times as many students per teacher at North HS as there are at West HS?
Student Teacher Ratios at Area High Schools
North RS
East HS
13
West HS
12
14
18
22
a.
b.
10
2 times
3 times
4 times
5 times
C.
d.

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