A random variable x has a mean of 120 and a standard deviation of 15. A random variable y has a mean of 100 and a standard deviation of 9. If x and y are independent, approximately what is the standard deviation of x - y ?.

Why do you think electric energy for households is generally supplied by power plants instead of by an electric generator at home.

Jim has found that he must consume 2,300 calories a day to reach his health goals, but he doesn't want to give up his afternoon snack of pretzels. unfortunately, he tends to eat the entire bag — which amounts to 1,300 calories! what strategy should jim use to improve his habits?

What is it called when someone gets sick from eating food contaminated with germs or toxins? a. potentially hazardous food b. ptomaine poisoning c. foodborne illness d. raw food