Q. Let X be a uniform discrete random variable which takes on the possible values of a,a+1,a+2,…,b. Calculate E(X) and Var(X).
Define X values: Define the random variable X and its possible values.X is a uniform discrete random variable which can take on the values a, a+1, a+2, ..., b. This means that each value is equally likely to occur.
Calculate E(X): Calculate the expected value E(X). The expected value of a uniform discrete random variable is the average of all possible values. To find E(X), we sum all the values from a to b and divide by the number of values.E(X)=b−a+1a+(a+1)+(a+2)+…+bThis is an arithmetic series with the first term a, the last term b, and the number of terms b−a+1.E(X)=[2a+b]∗b−a+1b−a+1E(X)=2a+b
Calculate Var(X): Calculate the variance Var(X). The variance of a uniform discrete random variable is given by the formula: Var(X)=12[(b−a+1)2−1] This formula comes from the fact that the variance is the average of the squared differences from the mean for all possible values. Var(X)=12[(b−a+1)2−1]
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