Can someone help me with this question please? ASAP

Five infinity stones cost $16.80. what is the price per infinity stone ?

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

Calculate the mean value (expected value) of the following discrete variable x (10 points): x = 0, 1, 2, 3, 4, 5, 6 p(x) = 0.2, 0.2, 0.15, 0.15, 0.15, 0.1, 0.05