Unit 3 Chapter 5 Section 6 Percent of Change.notebook
Bellringer:
January 26, 2016
Pg 13
1) Find the simple interest on $500 invested at a 3% annual interest rate for 4 years.
2) You can invest $200 at 4.5% simple interest for 6 years or at 8% for 3 years. Which investment earns you more money? How much is the interest?
Unit 3 Chapter 5 Section 6 Percent of Change.notebook
January 26, 2016
Unit 3
Chapter 5 Section 6
Finding Percent of Change
Objective: To find percents of increase and percents of decrease
Percent of Change: the percent a quantity
increases or decreases from
its original amount
amount of change
original amount
=
percent of change
100
Unit 3 Chapter 5 Section 6 Percent of Change.notebook
January 26, 2016
Examples:
Finding a Percent of Increase/Decrease
1) South Carolina had 6 seats in the U.S. House of Representatives in the 2000s. After the 2010 census, South Carolina had 7 seats. Find the percent of increase in the number of representatives.
2) A football player gained 1,200 yd last season and 900 yd this season. Find the percent of change. State whether the change is an increase or decrease.
Unit 3 Chapter 5 Section 6 Percent of Change.notebook
January 26, 2016
Markup: the difference between the selling
price and the store's cost of an item
amount of markup
original cost
=
percent of change
100
Finding a Percent of Markup
3) An electronics store orders sets of walkie­
talkies for $14.85 each. The store sells each set for $19.90. What is the percent of markup?
4) Find the percent of markup for a $17.95 headset marked up to $35.79.
Unit 3 Chapter 5 Section 6 Percent of Change.notebook
January 26, 2016
Discount: the difference between the original
price and sale price of an item
amount of discount
percent of change
=
original cost
100
Finding a Percent of Discount
5) During a clearance sale, a keyboard that normally sells for $49.99 is discounted to $34.99. What is the percent of discount?
6) Find the percent of discount of a $24.95 novel on sale for $14.97.
Unit 3 Chapter 5 Section 6 Percent of Change.notebook
Homework: January 26, 2016
Unit 3 Chapter 5 Section 6 Percent of Change.notebook
January 26, 2016
Percent Error: used to assure that products
meet specifications
Percent Error =
|Actual Value ­ Measured Value| X 100
Actual Value
Unit 3 Chapter 5 Section 6 Percent of Change.notebook
Percent Error
January 26, 2016
|Actual Value ­ Measured Value| X 100
Actual Value
8) The supervisor at a shoelace factory checks the length of 1 shoelace out of every 500 made. If shoelaces are not within 0.5% of the specified length, they will be rejected. 7
A 36­inch shoelace she just checked was 35 in long. 8
Does she reject this shoelace?
9) At a sporting good factory, a quality control technician checking the weights of baseball bats 1
measures a bat that should weigh 26 oz at 26 oz. If a 4
bat is not within 0.6% of its specified weight, it is rejected. Why does this bat pass of fail this test?