Answer:
The amount closest to Nathan's total costs after the 15% discount and 7% sales tax is <u> $609.</u>
Step-by-step explanation:
Given:
Nathan took his car in for service and repairs. He had a coupon for 15% off.
Original Prices
• Labor $275.85
• Parts $318.82
<u>• Other $74.61</u>
Total costs after the 15% discount and including 7% sales tax.
Now, to find the amount closest to Nathan's total cost.
Total cost before discount and tax:
Total cost = Adding prices of labor, parts and other.
Total cost = 
Total cost = $669.28.
Now, reducing the discount 15% :
<em>$669.28 - 15% of $669.28</em>
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Calculating the 15% discount we get:
⇒
⇒
.
The total cost after discount = $568.89
And, the total cost after including the sales tax:
<em>$568.89 + 7% of $568.89</em>
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Calculating the 7% tax we get:
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⇒
Total cost = $608.71.
An approximate value of the total cost = $609.
Therefore, the amount closest to Nathan's total costs after the 15% discount and 7% sales tax is $609.