The cost of the necklace before tax, for which Chris paid $9.18 including the sales tax of 8% is $8.5.
What is percentage increase ?
Percentage increase is the amount added to the initial value in the percentage part.
Chris paid $9.18 for a necklace. This amount includes a sales tax of 8%.
Let the cost of the necklace before tax is x dollars. Now, the 108% of the x is $9.18. Thus,
[tex]x\times\dfrac{100+8}{100}=9.18\\x=\dfrac{9.18\times100}{108}\\x=8.5[/tex]
Hence, the cost of the necklace before tax, for which Chris paid $9.18 including the sales tax of 8% is $8.5.
Learn more about the percentage increase here;
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