ANSWER
$-6.34
EXPLANATION
Let 'X' be the event with the net profit.
The expected value of X is:
[tex]E(X)=P(\text{ winning)}(420-7)+P(\text{ losing})(0-420)[/tex]The probability of winning is the probability of choosing 1 right number out of the 100 numbers of the raffle:
[tex]P(\text{wining)}=\frac{1}{100}[/tex]The probability of losing is the probability of getting any of the other numbers:
[tex]P(lo\sin g)=1-P(wining)=1-\frac{1}{100}=\frac{99}{100}[/tex]The exp
