Consider a large ferry that can accommodate cars and buses. the toll for cars is $3, and the toll for buses is $10. let x and y denote the number of cars and buses, respectively, carried on a single trip. cars and buses are accommodated on different levels of the ferry, so the number of buses accommodated on any trip is independent of the number of cars on the trip. suppose that x and y have the probability distributions shown below:
x 0 1 2 3 4 5
p(x) 0.06 0.09 0.26 0.28 0.20 0.11
y 0 1 2
p(y) 0.50 0.10 0.40
(a) compute the mean and standard deviation of x. (round the answers to three decimal places.)
mean of x
correct: your answer is correct.

standard deviation of x
incorrect: your answer is incorrect.

(b) compute the mean and standard deviation of y. (round the answers to three decimal places.)
mean of y
incorrect: your answer is incorrect.

standard deviation of y
incorrect: your answer is incorrect.

(c) compute the mean and variance of the total amount of money collected in tolls from cars. (round the answers to two decimal places.)
mean of the total amount of money collected in tolls from cars $
variance of the total amount of money collected in tolls from cars

(d) compute the mean and variance of the total amount of money collected in tolls from buses. (round the answers to one decimal place.)
mean of the total amount of money collected in tolls from buses $
variance of the total amount of money collected in tolls from buses

(e) compute the mean and variance of z = total number of vehicles (cars and buses) on the ferry. (round the answers to two decimal places.)
mean of z
variance of z

(f) compute the mean and variance of w = total amount of money collected in tolls. (round the answers to one decimal place.)
mean of w $
variance of w