You go to school is a college town. you know that there are 2000students enrolled in the school, but you don't know the population of the town, (without students). you walk up and down the main streets of the town, stop people, and ask them if they are studenys or not you ask 100 people, and 60 of them say they are students. estimate the nonstudent population of the town

If you ask 100 people and 60 say they are students, then you would assume that 60/100 people in town as a whole are students.  To estimate the non-student population, you would infer that the other 40 are not students, thus making the non-student to student ratio 40:60 or 2:3 when simplified.  This means that for every 2 non-students, there are 3 students.  If we multiply 2000 by this 2:3 ratio, we would see that 2/3*2000 = the non-student population.The non-student population is estimated at 1,333.