A bag contains a total of 150 green and blue marbles without looking a student. She’s a marble records, the color and placed it back in the back the student records for green marbles and 11 blue marbles, which is the best prediction of the total number of blue marbles in the bag.

Based on the student's recording of green marbles and blue marbles, the best prediction for the total number of blue marbles in the bag would be around 11 blue marbles. Since the student recorded 11 blue marbles out of the total 150 marbles, it is likely that there are around 11 blue marbles in the bag.