Pre-Test Question:

Chapter 5. Chapter 5 Percentage Change

Math and Graphing Review
true
true
You must read each slide, and complete any questions on the slide, in sequence.

Last week the price of orange juice was $4. This week you discover the price has risen to $5. What was the percentage change in the price of orange juice since last week?

A.
B.
C.
D.
Correct! The price of orange juice rose by 25%.
Sorry, the price of orange juice rose by 25%. To determine the percentage change use the formula for percentage change: (5-4)/4=1/4=0.25=25%

1.

This week there is a sale on HD TVs. One TV you are looking at was originally $1250. Today it is on sale for $1000. What is the percentage change?

A.
B.
C.
D.
Correct! The price of the TV decreased by 20%.
Sorry, the price of the TV decrease by 20%. To determine the percentage change use the formula for percentage change: (1000-1250)/1250=-250/1250=-0.2=-20%

2.

Another TV that you are looking at buying is on sale from $1000 to $900. What is the change in price?

A.
B.
C.
D.
Correct! The price of this TV was decreased $100.
Sorry, the price of this TV was decreased $100. To determine the change in variable use the formula for change in variable: 900-1000=-100

3.

You are having a Super bowl party at your house. 12 friends originally said that they were coming. On the day of the game, you hear from another 4 friends who decided last minute that they can make it, increasing your guest count to 16 people. What is the percentage change in party guests?

A.
B.
C.
D.
Correct! The guest count increased by 33.3%.
Sorry, the guest count increased by 33.3%. To determine the percentage change use the formula for percentage change: (12-16)/12=4/12=0.333=33.3%

4.

For Halloween you bought a bag of 500 pieces of mixed candy. After just one hour you see that you only have 350 pieces left for the rest of the evening. What is the percentage change in candy after that first hour?

A.
B.
C.
D.
Correct! The amount of candy on hand decreased by 30%.
Sorry, the amount of candy on hand decreased by 30%.. To determine the percentage change use the formula for percentage change: (500-350)/500=-150/500=-0.30=-30%

5.

Gas prices are up for the holiday weekend. Last week gas was $3.29 per gallon and now it is $3.49. What is the percentage change in gas price since last week?

A.
B.
C.
D.
Correct! The price of gas rose by 6.08%.
Sorry, the price of gas rose by 6.08%. To determine the percentage change use the formula for percentage change: (3.29-3.49)/3.29=.2/3.29=0.0608=6.08%