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11 votes
11 votes
Mark bought 20 toy cars for $15. Tina

bought 12 toy cars for $8. Use cross
products to determine if the given rates
are proportional.
A) Yes, the two rates are proportional.
B) No, the two rates are not proportional.

User Will Manley
by
2.1k points

1 Answer

24 votes
24 votes

Answer: B) No, the two rates are not proportional

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Step-by-step explanation:

The first sentence given leads to the fraction 20/15

The second sentence gives us 12/8

If the rates are proportional, then the fractions would be equal.

For now, assume they are equal. Cross multiply to get the following:

20/15 = 12/8

20*8 = 15*12

160 = 180

The two sides lead to different values, so the original equation is false. The rates are not proportional

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Another way we can see that the fractions aren't the same is to use a calculator or long division to get the decimal form

  • 20/15 = 1.33 (approx)
  • 12/8 = 1.5

The decimal values must be the same if we want the fractions to be equal as well.

User Demarsch
by
3.2k points