A box contains a yellow ball, an orange ball, a green ball, and a blue ball. Billy randomly selects 4 balls from the box (with replacement). What is the expected value for the number of distinct colored balls Billy will select?

Respuesta :

Answer:

[tex]Expected = 0.09375[/tex]

Step-by-step explanation:

Given

[tex]Balls = 4[/tex]

[tex]n = 4[/tex] --- selection

Required

The expected distinct colored balls

The probability of selecting one of the 4 balls is:

[tex]P = \frac{1}{4}[/tex]

The probability of selecting different balls in each selection is:

[tex]Pr = (\frac{1}{4})^n[/tex]

Substitute 4 for n

[tex]Pr = (\frac{1}{4})^4[/tex]

[tex]Pr = \frac{1}{256}[/tex]

The number of arrangement of the 4 balls is:

[tex]Arrangement = 4![/tex]

So, we have:

[tex]Arrangement = 4*3*2*1[/tex]

[tex]Arrangement = 24[/tex]

The expected number of distinct color is:

[tex]Expected = Arrangement * Pr[/tex]

[tex]Expected = 24 * \frac{1}{256}[/tex]

[tex]Expected = \frac{3}{32}[/tex]

[tex]Expected = 0.09375[/tex]