Question

You throw two four-sided dice. Let the random variable X represent the maximum value of the two dice. Compute E(X). Round your answer to three decimal places.

Answer 1

Answer:

E(X)=3.125

Step-by-step explanation:

We are given that two four sided dice.

Then , the sample space

{(1,1),(1,2),(1,3),(1,4),(2,1),(2,2),(2,3),(2,4),(3,1),(3,2),(3,3),(3,4),(4,1),(4,2),(4,3),(4,4)}

Total number of outcomes=16

Let the random variable X represent the maximum value of the two dice

Outcomes                            X                                 P(X)

(1,1)                                          1                                 1/16

(1,2),(2,1),(2,2)                                   2                        3/16

(1,3),(2,3),(3,1),(3,2),(3,3)                    3                           5/16  

(1,4),(3,4) ,(2,4),(4,1),(4,2),(4,3),(4,4)    4                            7/16

Using the probability formula

$P(E)=\frac{Favorable\;outcomes}{Total\;number\;of\;outcomes}$

Now,

$E(X)=\sum_{i=1}^{n}x_iP(x_i)$

$E(x)=1(1/16)+2(3/16)+3(5/16)+4(7/16)$

$E(x)=\frac{1+6+15+28}{16}$

$E(x)=\frac{50}{16}=3.125$