Stats Question Suppose a random variable X has a probability distribution given
ID: 3204810 • Letter: S
Question
Stats Question
Suppose a random variable X has a probability distribution given by: A single experiment generates a random value from this distribution. If the experiment is repeated many times: What will be the approximate proportion of times that the value is -1? Give a reason for your answer. What will be the approximate value of the sample mean of these random variables? Give a reason for your answer Calculate the mean and variance of this distribution. Let Y = 3X - 2. What are the rules that relate the mean and variance of Y to the mean and variance of X? Use these rules to find the mean and variance of y.Explanation / Answer
(i)Approximate proportion for x=-1 is 0.3=3/10
This is because of the law of large numbers.
(ii)Mean=-1*0.3+2*0.7=1.1
b)Mean=1.1
Variance=0.3*(-1-1.1)^2+0.7*(2-1.1)^2= 1.89
c)Y=2X-2
E[Y]=2*1.1-2=0.2
V[Y]=4*1.89=7.56