Answer:
$0.68
Explanation:
Multiply each possible prize by its likelihood and add the results in order to obtain the expected value (Note that there is a 100% of losing 0.57 cents since that is the cost of entry):
[tex]EV = 5200*\frac{1}{8900} +2500*\frac{1}{6400} +900*\frac{1}{3900}+100*\frac{1}{2100} -0.57*1\\EV= \$0.68[/tex]
The expected value of the amount won for one entry if the cost of entering is 57 cents is $0.68