solve the questions below. please explain how to solve step by step.

Question 3 1 pts Suppose that a random variable X modelling the number of sh in a tank that will be eaten by other sh has possible values 0, 1, and 2. The probability that 0 are eaten is 0.2 and the probability that 1 is eaten is 0.2. What is the expected number that will be eaten? E Question 4 1 pts Suppose that a marine biologist will draw a random number. She will then add 4 times this number of grams of plankton to a tank. If the tank has 52g of plankton to begin with, and if the expected value of the random number is 7, what amount of plankton do you expect to be in the tank afterwards? E Question 5 1 pts Suppose that a marine biologist will draw a random number. She will then add 6 times this number of grams of plankton to a tank. If the tank has 135g of plankton to begin with, and if the standard deviation of the random number is 5, what is the standard deviation of the amount of plankton that will be in the tank afterwards? E