Since Jan completes 60 trials and pulled green 15 times, the probability of any marble being green can be calculated as:
= 15/60
= 0.25
With 250 marbles in the bag, using the probability value of green marbles calculated above, the number of green marbles can be estimated as:
= 0.25 of 250
= 62.5
This shows that since there is a 25% probability of obtaining a green marble from 60 trials of pulling colored marbles out of the bag containing 250 marbles, then the total number of green marbles will be equal to 62 or 63.
