The number of telephone calls that arrive at a phone exchange is often modeled as a Poisson random variable. Assume that on the average there are 15 calls per hour. What is the probability that there are more than 20 calls in one hour?

One light bulb is selected at random from a lot of 140 light bulbs, of which 5% are defective. What is the probability that the light bulb selected is defective?

Imagine that you are training to run a half-marathon and so every week you have 2 intense days, 3 light days, and 2 rest days. On your intense days you run 16 km, on your light days you run 5 km, and on your rest days you do not run. How would you model your miles run per day as a random variable? (Hint: probability distribution)

The mosquitos are out in your back yard, and they bite you at random times. Each bite happens independently of the last bite. The average time between bites is 2.501 minutes. What is the probability that it takes longer than 1 minutes for them to first bite you?

The table summarizes results from 986 pedestrian deaths that were caused by automobile accidents. DriverIntoxicated? Pedestrian Intoxicated?                           Yes                               No Yes 58 81 No 240 607 If two different pedestrian deaths are randomly selected, find the probability that they both involved drivers that were intoxicated.

A professional tennis player claims to get 90% of her second serves in. In a recent match, the player missed 5 of her first 20 second serves. Is this a surprising result if the player's claim is true? Assume that the player has a 0.10 probability of missing each second serve. We want to carry out a simulation to estimate the probability that she would miss 5 or more of her first 20 second serves. The dotplot displays the number of second serves missed by the player out of the first 20 second serves in 100 simulated matches. ▪………………………. ●●●●●●●●●●●●●● A●●●●●●●● …………….. 1 2 3 4 5 6 Number of missed serves in simulated match 7 Is there convincing evidence that the player misses more than 10% of her second serves? Why or why not? No, there is not convincing evidence that the player misses more than 10% of her second serves. Missing 5 out of 20 is better than expected. No, there is not convincing evidence that the player misses more than 10% of her second serves. Assuming the player makes…