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Mathematics Methods · Unit 3 · Topic 3.3

Discrete random variables

5 free questions, 4 calculator-free and 1 calculator-assumed, with worked solutions written like marking keys.

Calculator-freestandard

A discrete random variable XX has the probability distribution P(X=1)=0.1P(X=1)=0.1, P(X=2)=0.2P(X=2)=0.2, P(X=3)=0.3P(X=3)=0.3, P(X=4)=0.4P(X=4)=0.4. Determine E(X)E(X).

Calculator-freefoundation

A fair six-sided die is rolled once and XX is the number showing. Determine P(X=3)P(X=3).

Calculator-freefoundation

A Bernoulli random variable has parameter p=0.3p = 0.3. Determine its variance.

Calculator-assumedfoundation

For X∼B(10,0.3)X \sim B(10, 0.3), determine the mean of XX.

Calculator-freefoundation

In 200200 trials an outcome occurred 5050 times. Determine the point estimate of its probability.