I can see you come from outside the USA. No insults intended!!
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Anyways, we have to put one side of the ratio and match it to 48.
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Or even better...
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MAKE!!
A!!
PROPORTION!!
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So... Let's say 7 is proportional to 48... so 7/5 = 48/x, where x is the number equivalent to ratio of 5.
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Cross multiply!!
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7x = 240.
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Divide 7 on both sides.
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x = 34 2/7.
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Hope I helped!!