A coin is tossed four times. Let X denote the number of times a head appears. What would be the expected value of X?

Question

Random      |Probability(p) |            A. zero(0)
Variable(x)  |                    |            B. 1

------------- |--------------- |            C. 2

       0         |        1/16      |            D. 3

       1         |        4/16      |

       2         |        6/16      | 

       3         |        4/16      |

       4         |        1/16      |

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Answer 1

In a binomial distribution the expected value is np. In your example n=4 and p=p(H).

 

Uriah, Among other courses I teach probability. I would suggest a regular tutoring session where we could go over all your questions with as much explanation as necessary.

 

Arnold