Question

At the school book sale, Michael bought 3 books for $6. Darnell bought 5 books for $10. Are these rates proportional?

Answer 1

Michael:
3 books = $6
1 book = $6 ÷ 3 = $2

Darnell:
5 books = $10
1 book = $10 ÷ 5 = $2

Both Michael and Darnell bought their book at $2/book. The rates are proportional.

Answer Yes, the rate of proportional.

Answer 2

3 for $6 = 6/3 = $2/book
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             Michael
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5 for $10 = 10/5 = $2/book
---------------↑-------------------
              Darnell
_____________________________________________________________

Yes,they can form a proportion because they are equal

Hope this helps :)