Tyler says he invented a number puzzle he asked Claire's to pick a number then ask her to do the following triple the number
subtract 7
double the result
subtract 22
divide by 6
Clara says that now she has a -3 Tyler says that her original number must have been 3 how did Tyler know that explain your reasoning

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