Most plumbing companies charge a fee to come to your house plus a charge per hour of work. The fees and charges for two plumbing companies are shown. Company A Fee: $50 Charge per hour: $40 Company B Fee: $25 Charge per hour: $50

Write an equation for each company, where c = total cost (in dollars) and h = number of hours. Explain what the initial values and rates of change mean in this context.

Company A: Company B:

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