Sarah asked 20 people at a tennis tournament how they travelled there. She found that 13 of them travelled by car. Estimate how many of the total 2000 people at the tournament travelled by car.

First calculate the fraction of the sample that travelled by car to be 13/20.Next multiply the total population size by this proportion to find the estimate of the total number of people who travelled by car, 2000 x 13/20 = 1300.