P(Xi) = .2 (equal chance of picking each case)
LET: X1 = 1 X2 = 10 X3 = 100 X4 = 1000 X5 = 10000
REMAINING AVERAGE VALUE IF THE FIRST CASE PICKED IS: X1 - $2777.50 X2 - $2775.25 X3 - $2752.75 X4 - $2527.75 X5 - $277.75
THEREFORE (BY DEFINITION) E[XI] = .2 * (2777.50 + 2775.25 + 2752.75 + 2527.75 + 277.75) = $2222.20
