3 A bag contains 60 red or black markers.
 Each student in Mr. Jones's class selects a
 random sample of 15 markers from the bag,
 counts the number of black markers, and
 returns the sample to the bag. What is a
 reasonable estimate for the number of black
 markers in the bag? Show your work.
 8 9 10 11 12 13
 Number of Black Markers