Making Predictions

Using Proportions

Prediction

is a guess about something in the future. One way to make a prediction is to collect information by conducting a survey. The population is the whole group being surveyed. To save time and money, researchers often make predictions based on a sample, which is part of the group being surveyed.

We can use proportions to solve problems about predictions.


Example #1

A store claims that 78% of shoppers end up buying something. Out of 1,000 shoppers, how many would you predict buy something?

You can write a proportion. Remember that percent means 'per hundred'.


Example #2

Based on a sample survey, a local newspaper states that 3 out of 25 of the city's residents have volunteered at an animal shelter. Out of 5,000 residents, how many would you predict have volunteered at the animal shelter?


Practice #1: Now you try.

Based on a sample survey, a local newspaper claims that 64% of the town's households receive their paper. Out of 15,000 households, how many would you predict receive their paper?


Practice #2: Try one more.

Based on a sample survey, 13 out of 50 local people have a pet dog. Out of 600 people, how many people do you predict will have a pet dog?