Let X∼Po(3) and Y∼Po(5) be independent random variables. Find P(X+Y=8).
[3]
Question 2
Skill question
Let X∼Poisson(λ1) and Y∼Poisson(λ2) be independent random variables. Determine Var(aX+bY) in terms of a,b,λ1, and λ2.
[3]
Question 3
Skill question
A factory has two machines producing defects independently with rates Po(2) and Po(1.5) per day. Find the probability that fewer than 3 defects occur in total in a single day.
[4]
Question 4
Skill question
Find the moment generating function MZ(t) of Z=2X+3Y where X∼Po(λ1) and Y∼Po(λ2) are independent random variables.
[3]
Question 5
Skill question
If X∼Poisson(λ) satisfies P(X=0)=0.05, find the value of λ.
[3]
Question 6
Skill question
Given independent X∼Poisson(2) and Y∼Poisson(3), find the conditional distribution of X given X+Y=5.
[3]
Question 7
Skill question
Let X∼Po(λ1) and Y∼Po(λ2) be independent random variables.
Show that X+Y∼Po(λ1+λ2).
[5]
Question 8
Skill question
Independent random variables X and Y are such that X∼Po(4) and Y∼Po(6).
Show that P(X−Y=1)=4e−10∑y=0∞y!(y+1)!24y.
[5]
Question 9
Skill question
Given independent random variables X∼Po(x+5) and Y∼Po(x2−6), and E(6X+Y)=16, find the value of x.
[6]
Question 10
Skill question
Determine the mean and the variance of Z=4X−2Y, given that X and Y are independent random variables with X∼Po(3) and Y∼Po(4).
[4]
Question 11
Skill question
Call centre A receives calls according to a Poisson process at a rate of 5 calls per hour, and call centre B at a rate of 3 calls per hour.
Calculate the probability that exactly 16 calls are received in total during a 2-hour period.
[3]
Question 12
Skill question
Restaurant X receives on average 4 orders per minute and restaurant Y receives 2 orders per minute. Assuming independence, what is the probability that in a 10-minute period they receive more than 70 orders in total?