
Solution :
Colored marble       Prize
   Red ----  10        20
  Blue --- 38         10
  Green --- 26        5
P(red) Â = Â 10/74 Â = Â 5/37
P(blue) Â = Â 38/74 Â = Â 19/37
P( green) Â = 26/74 Â = Â 13/37
Therefore,
 X    →   Red      Blue    Green
P(X) Â Â Â Â Â 5/37 Â Â Â Â 19/37 Â Â Â 13/37
The expected values are :
[tex]$20 \times \frac{5}{37} - 10 \times \frac{19}{37} - 5 \times \frac{13}{37}[/tex]
= -4.189
Thus it is not profitable to play the game.