[quote]A company manufactures car parts. As is the case with any system of mass production, small errors in production of every part occur. To make viable car parts, the company must make sure the unavoidable errors occur only within a specific range. The company knows that a particular part they manufacture will not work if it weighs less than 98% of its target weight or more than 102% of its target weight. If the target weight of this piece is [b]20.5[/b] grams, what is the range of weights the part must fall within for it to function? The car part must weigh between [b].98 × 21.5 = 21.07[/b] grams and [b]1.02 × 21.5 = 21.93 [/b]grams. The problem states that the part cannot weigh less than the minimum weight or more than the maximum weight in order for it to work. This means that the part will function at boundary weights themselves, and the lower and upper bounds are included. The answer to the problem is 21.07 [u]<[/u] x [u]<[/u] 21.93, where x is the weight of the part in grams.[/quote]WTF I thought the target weight was 20.5, so why are you multiplying by 21.5? So confuse. [url=http://www.sparknotes.com/testprep/books/newsat/chapter19section7.rhtml]source[/url]