Your school’s baseball team sells 1250 raffle tickets at $4 each. The grand prize is a $3000 boat. The second prize is a $450 grill. There are also ten $25 gift certificates. Calculate the expected value of the winnings for a single-ticket purchase. Show the work that leads to your answer.

Respuesta :

Answer:

The expected value of the winnings for a single-ticket purchase is -$1.0016.

Step-by-step explanation:

The total number of tickets sold is, N = 1250.

Cost of one ticket is, $4.

Let X = amount of prize.

The prize distribution is as follows:

1 Grand price = $3000

1 Second prize = $450

10 Third prize = $25

The expected value X can be computed using the formula:

[tex]E(X)=\sum x.P(X)[/tex]

Compute the probability distribution of X as follows:

     Prize        Amount (X)         P (X)                    x · P (X)

1 Grand prize    $3000         [tex]\frac{1}{1250}=0.0008[/tex]     [tex]\$3000\times 0.0008=2.4[/tex]

1 Second prize  $450          [tex]\frac{1}{1249}=0.0008[/tex]      [tex]\$450\times 0.0008=0.36[/tex]

10 Third prize      $25          [tex]\frac{10}{1248}=0.008[/tex]        [tex]\$25\times 0.008=0.2[/tex]

No prize             -$4      [tex]1-\sum P(Win)\\=0.9904[/tex]   [tex]-\$4\times 0.9904=-3.9616[/tex]

TOTAL                              1.0000                            -1.0016

Thus, the expected value of the winnings for a single-ticket purchase is -$1.0016.