Tristan records the number of customers who visit the store each hour on a Saturday. His data representing the first seven hours are 15, 23, 12, 28, 20, 18, and 23. How many customers visited the store during the eighth hour if the median number of customers per hour did not change? 16 19 20 23

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