Ariel threw a ball from the height of 6 feet into a pond. The function h (t)= –16t2 + 48t + 6 is used to calculate the amount of time the balls in the air before it hits the ground. How long was the ball in the air? How many solutions does this quadratic function have?

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