Question 996001
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X=cost of 3.5 lbs
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Set up as a ratio:
{{{11.60/(4lbs)=X/(3.5lbs)}}}
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Look at what is happening: The left side is 
calculating the price per pound, so when we multiply
by 3.5lbs, we are multiplying cost per pound by pounds:
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{{{(3.5lbs)(11.60/(4lbs))=X}}}
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{{{(3.5lbs)(2.90/lb)=X}}} (Notice the price per pound is 2.90)

{{{10.15=X}}}
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ANSWER: The price of 3.5 pounds is 10.15.