Poisson Distribution

This is not making sense to me, help would be appreciated. In a Poisson distribution u = 4. a. What is the probability that x = 2. b. What is the probability that x > 2.

Three defective electric toothbrushes were accidentally shipped to a drug store called Clean-brush products along with 17 non-defective ones.

I have a probability exercise I don't know how to resolve - Three defective electric toothbrushes were accidentally shipped to a drug store called Clean-brush products along with 17 non-defective ones. a. What is the probability the first two electric toothbrushes sold will be returned to the drugstore because they are defective? b. What is the probability the first two electric toothbrushes sold will not be defective?

Probability

I need help with this question: Bank of America customers select their own 3 digit personal identification number ( pin )for use at ATM’s. a. Think of this as an experiment and list four possible outcomes. b. What is the probability Mr. Jones and Mrs. Smith select the same pin? c. Which concept of probability do you use to answer b.?

Probability

I'm not sure how to figure this one out - A quality control inspector selects a part to be tested. The part is then declared acceptable, repairable, or scrapped. Then another part is tested. List the possible outcomes of this experiment regarding two parts.

Variables - discreet and continuous random variables

I'm having problems with this one - Which of these variables are discreet and which are continuous random variables? a. The number of new accounts established by a salesperson in a year. b. The time between customer arrivals to a bank ATM. c. The number of customers in Big Nick’s barber shop. d. The amount of fuel in your car’s gas tank. e. The number of minorities on a jury. f. The outside temperature today.