Question

Suppose you and a friend are playing a game that involves flipping a fair coin 3 times. Let X = the number of times that the coin shows heads. The probability distribution of X is shown in the table.

The expected number of heads is _____.

The standard deviation of the number of heads is ____. Round to three decimal places.

Answer 1

Question 1

The probability of tossing a head is
`(1)/(2)`, making the answer
`3\left((1)/(2) \right)=\boxed{1.5}`.

Question 2

`(3)(1/2)(1/2)(1/2)=\boxed{0.375}`