If a tree casts a 24 foot shadow while a yardstick casts a 2 foot shadow what’s the height of the tree ? Need help please ASAP

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Prove that 16^4-2^13-4^5 is divisible by 11.

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