SOLUTION: Let X be a discrete random variable whose values lie in {0, 1, 2, ...} with probability mass function {{{f(x)=(1/ex!)}}} . Find P(X ≤ 2) and P(X > 2)

Algebra ->  Probability-and-statistics -> SOLUTION: Let X be a discrete random variable whose values lie in {0, 1, 2, ...} with probability mass function {{{f(x)=(1/ex!)}}} . Find P(X ≤ 2) and P(X > 2)      Log On


   

Question 1136605: Let X be a discrete random variable whose values lie in {0, 1, 2, ...} with probability mass function f%28x%29=%281%2Fex%21%29 . Find P(X ≤ 2) and P(X > 2)
Answer by ikleyn(52890) About Me  (Show Source):
You can put this solution on YOUR website!
.

P(X <= 2 ) = P(0) + P(1) + P(2) = %281%2Fe%29%2A%281%2F1+%2B+1%2F1+%2B+1%2F2%29 = %281%2Fe%29%2A%281+%2B+1+%2B+1%2F2%29 = %281%2F2.71828%29%2A%281+%2B+1+%2B+1%2F2%29 = use your calculator.



P( X > 2 ) = complement to  P( X <=2 ) = 1 - P(X <=2 ) = see the line above = 1 - %281%2F2.71828%29%2A%281+%2B+1+%2B+1%2F2%29 = use your calculator.