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Find ⓐ the sales tax and ⓑ the total cost: Alexandra bought a television set for $\text{\$724}$ in Boston, where the sales tax rate was $\text{6.25\%}$ of the purchase price.
Find ⓐ the sales tax and ⓑ the total cost: Kim bought a winter coat for $\text{\$250}$ in St. Louis, where the sales tax rate was $\text{8.2\%}$ of the purchase price.
Evelyn bought a new smartphone for $\text{\$499}$ plus tax. She was surprised when she got the receipt and saw that the tax was $\text{\$42.42}.$ What was the sales tax rate for this purchase?
Identify what you are asked to find.  What is the sales tax rate? 
Choose a variable to represent it.  Let $r=$ sales tax. 
Write a sentence that gives the information to find it.  What percent of the price is the sales tax? 
Translate into an equation.  
Divide.  
Simplify.  
Change to percent form.  
Check. Is this answer reasonable?  
Yes, because 8.5% is close to 10%.
10% of $500 is $50, which is close to $42.42. 

Write a complete sentence that answers the question.  The sales tax rate is 8.5%. 
Diego bought a new car for $\text{\$26,525}.$ He was surprised that the dealer then added $\text{\$2,387.25}.$ What was the sales tax rate for this purchase?
9%
What is the sales tax rate if a $\text{\$7,594}$ purchase will have $\text{\$569.55}$ of sales tax added to it?
7.5%
Sales people often receive a commission , or percent of total sales, for their sales. Their income may be just the commission they earn, or it may be their commission added to their hourly wages or salary. The commission they earn is calculated as a certain percent of the price of each item they sell. That percent is called the rate of commission .
A commission is a percentage of total sales as determined by the rate of commission.
To find the commission on a sale, multiply the rate of commission by the total sales. Just as we did for computing sales tax, remember to first convert the rate of commission from a percent to a decimal.
Helene is a realtor. She receives $\text{3\%}$ commission when she sells a house. How much commission will she receive for selling a house that costs $\text{\$260,000}?$
Identify what you are asked to find.  What is the commission? 
Choose a variable to represent it.  Let $c=$ the commission. 
Write a sentence that gives the information to find it.  The commission is 3% of the price. 
Translate into an equation.  
Simplify.  
Change to percent form.  
Check. Is this answer reasonable?  
Yes. 1% of $260,000 is $2,600, and $7,800 is three times $2,600.  
Write a complete sentence that answers the question.  Helene will receive a commission of $7,800. 
Bob is a travel agent. He receives $\text{7\%}$ commission when he books a cruise for a customer. How much commission will he receive for booking a $\text{\$3,900}$ cruise?
$273
Fernando receives $\text{18\%}$ commission when he makes a computer sale. How much commission will he receive for selling a computer for $\text{\$2,190}?$
$394.20
Rikki earned $\text{\$87}$ commission when she sold a $\text{\$1,450}$ stove. What rate of commission did she get?
Identify what you are asked to find.  What is the rate of commission? 
Choose a variable to represent it.  Let $r=$ the rate of commission. 
Write a sentence that gives the information to find it.  The commission is what percent of the sale? 
Translate into an equation.  
Divide.  
Simplify.  
Change to percent form.  
Write a complete sentence that answers the question.  The commission was 6% of the price of the stove. 
Check if this answer is reasonable.  Yes. A 10% commission would have been $145.
The 6% commission, $87, is a little more than half of that. 
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