Arrivals to a bank automated teller machine (ATM) are distributed according to a Poisson distribution with a

Question:

Arrivals to a bank automated teller machine (ATM) are distributed according to a Poisson with a mean equal to three per 15 minutes.
a. Determine the probability that in a given 15-minute segment, no customers will arrive at the ATM.
b. What is the probability that fewer than four customers will arrive in a 30-minute segment? Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...