Question

Determine if the following ratios/rates are proportional. Write proportional if the ratios form a

proportion and not proportional if they do not.

Answer 1

I'll do problems 8 through 10 to get you started.

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Problem 8

5/8 = 2/3

5*3 = 8*2 ... cross multiplying

15 = 16

The last equation is false so the first equation is also false

Therefore, 5/8 and 2/3 are not proportional.

Note: The cross multiplying rule has us go from A/B = C/D to A*D = B*C.

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Problem 9

7/3 = 14/6

7*6 = 3*14 ... cross multiplying

42 = 42

The last equation is true so the first equation is also true

Therefore, 7/3 and 14/6 are proportional

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Problem 10

We could use the cross multiplying trick done with the previous problems.

But this time I'll use a different approach.

Grab a calculator, or use long division, to find that:

• 16/9 =1.778 approximately
• 11/6 = 1.833 approximately

The results are not the same, so the equation 16/9 = 11/6 is false

Therefore, 16/9 and 11/6 are not proportional.