1. At a bake sale, a dozen cookies sold for $4. This price was 80% of the original price. What was the original price? If 12 cookies are for $4

When you answer this can you explain

Y+ 2/y is it a polynomial in one variable or not? and if so, why?

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