## MATH 399N Week 4 Homework Solutions: → Spring 2017

Determine whether the random variable is discrete or continuous.

Q. The number of textbook authors now sitting at a computer

Q. The number of free-throw attempts before the first shot is made

Q. The time required to download a file from the Internet.

Q. The number of bald eagles in the country.

Q. The height of a randomly selected giraffe.

Q. x represents the number of dependent children in a household. Is it discrete or continuous?

Q. Find the probability of randomly selecting a household that has fewer than two dogs.

Q. Find the probability of randomly selecting a household that has at least one dog.

Q. Find the probability of randomly selecting a household that has between one and three dogs, inclusive.

Q. Find the variance of the probability distribution

Q. Find the std dev of the probability distribution (square root of 2.3)

Q. Interpret the results

Q. mean?

Q. variance?

Q. std dev?

Q. P(5)

Q. P(x≥6)

Q. P(x<4)

Q. Given that x has a Poisson distribution with μ=66, what is the probability that