Converting a Fraction to a Percentage in a Real-World Situation

Introduction

In this lesson, we solve real world problems involving conversion of fractions into percentages.Example 1

In a survey one in five people said they preferred a certain brand of fast food. Write this figure as a percentage.

Solution

Step 1:

The fraction of people preferring a certain brand of fast food = 1515

Step 2:

We multiply and divide the fraction by 20

15=(1×20)÷(5×20)=2010015=(1×20)÷(5×20)=20100

Step 3:

Writing this fraction as a percentage

By definition, 2010020100 = 20%

So, 1515 = 20%Example 2

Jamila is working out a problem involving 2323. She needs to enter this fraction into a calculator. How would she enter 1414 as a decimal on the calculator?

Solution

Step 1:

The fraction of people preferring a certain brand of fast food = 2323 On long division

2323 = 0.6667

Step 2:

We multiply the decimal by 100

0.6667×100=66.67%0.6667×100=66.67%

Step 3:

So, 2323 = 66.67%Example 3

In a clearance sale, a shop offers 30% off the original prices. What fraction is taken off the prices?

Solution

Step 1:

The percentage off on original prices in the shop = 30%

Step 2:

By definition of percent

30% = 30100=31030100=310

Step 3:

So, 30% = 310