Calculating Percent Change and Population

The video tutorial explains how to calculate percent increase and decrease using proportions. It covers the method of finding the change over the original value and equating it to the percent over 100. Two examples are provided: one for calculating the percent decrease in the price of a sofa and another for calculating the percent increase in a town's population. The tutorial emphasizes the importance of using the original value in the denominator and provides step-by-step calculations, including finding the least common denominator and solving equations.

What is the basic formula for calculating percent increase or decrease?

• Change over new equals percent over 100

• Change over original equals percent over 100

• Original over change equals percent over 100

• New over change equals percent over 100

In Example 1, what is the original price of the sofa?

• $179.00

• $419.00

• $299.00

• $120.00

What is the new price of the sofa during the sale in Example 1?

• $120.00

• $299.00

• $419.00

• $179.00

How do you calculate the change in price for Example 1?

• New minus original

• New plus original

• Original minus new

• Original plus new

What is the percent decrease in the price of the sofa?

• 50.00%

• 70.00%

• 40.13%

• 60.00%

What is the first step in solving the equation for percent increase or decrease?

• Add the original to the new

• Subtract the original from the new

• Find the least common denominator

• Multiply both sides by 100

In Example 1, what is the result of 299 minus 179?

• 160

• 100

• 120

• 140

In Example 2, what was the original population of the town in 1990?

• 12,345

• 25,000

• 19,071

• 31,416

What was the population of the town in 2000 in Example 2?

• 12,345

• 19,071

• 31,416

• 25,000

How do you calculate the change in population for Example 2?

• Original minus new

• New minus original

• New plus original

• Original plus new