PROBABILITY

  PROBABILITY

MEAN OR EXPECTATION


1. Let a pair of dice be thrown and the random variable X be the sum of the numbers that appear on the two dice.  Find the mean or expectation of X.


2. Find the mean of X where X denotes the number obtained on a throw of an unbiased die.


3. A coin is biased so that head is 3 times as likely to occur as tail.  If the coin is tossed twice, find the mean of X where X denotes the number of tails.


4. Find the mean of the numbers obtained on throwing a die having written 1 on three faces, 2 on two faces, and 5 on one face.

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