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In a group of 12 astronauts, 5 of them are experts in exobiology. Out of the...

In a group of 12 astronauts, 5 of them are experts in exobiology. Out of the 12 astronauts, 3 are randomly selected (without replacement) to be on the next mission. Let X be the number of experts selected for the mission:

a) Find the probability mass function of X (i.e. Fill out your final answers in the table): x P(X = x)

b) Based on your answer in a) find V ar(1.3 − 6.2X). Circle your final answer. Hint: It may be helpful to first find Var(X).

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