A discrete random variable has probability function for . Find the exact value of .

Answer and explanation

Correct answer: D.

  1. Step 1: Probabilities sum to 1: .
  2. Step 2: So and .
Answer
1/10.
Why not the others: sums only ; counts the four outcomes; drops the first term.

Practise more Probability, Binomial and Normal Distributions.

Free questions with an explanation for every one, and full timed Victorian VCE mock tests.