An extrapolation is when you take a small set of data and apply it to a larger set. For example. 3 out of 4 kids enjoyed reading Because of Winn Dixie. You can extrapolate that data to predict how many students in the entire class enjoyed the book. ³/₄ is equivalent to ²¹/₂₈.
Which of the following is a reasonable prediction of the number of students who enjoyed reading Because of Winn Dixie in a 28 member class?

You need to be careful about populations when extrapolating data. If the survey population is preschoolers, then you can only extrapolate to preschoolers. 4 out of 5 preschoolers thought that Sesame Street was worth their time to watch. Would it make sense to extrapolate that data and say that 120 of our 150 eight graders believe that Sesame Street is worth their time?

The Marsh Pride of lions is one of the most successful lion prides studied. About one out of every six of their hunts resulted in a kill. About how many meals should we expect them to get if they hunt 36 times?

The Pet Mart manager polled people entering his store and found that 4 out of 10 pet owners take their pets to the vet on a regular basis (whether they are sick or not). Which of the following populations could you extrapolate this data to?

3 out of 5 pet owners report that their pet has bitten them. Of 100 people at the dog show, how many would you expect to have been bitten by their pet?

During the post-manufacturing inspection, 1 out of 20 Drool Catchers had to be discarded for various imperfections. How many Drool Catchers would you expect to throw away if you manufactured 10,000?

We asked 40 middle school students to choose between Frosted Mini Wheat and Raisin Bran. 32 of the students chose Frosted Mini Wheat. In a school of 500 students, how many would you expect to choose Frosted Mini Wheat?

Here is a fantastic way to use extrapolation!
Elizabeth can simplify 5 fractions in 2 minutes. About how many minutes will it take her to simplify the 40 fractions that Mr. Mitchell assigned as homework?