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How Do You Determine if Two Ratios are Proportional Using Cross Products?

Determine if the following ratios form a proportion: 4/9, 9/11

Summary

  1. The '?' over the '=' indicates we don't know if this is a true statement.
  2. 4x11=44
  3. 5x9=45
  4. ≠ means not equal
  5. The ratios or cross-products must be equal to form a proportion.

Notes

    1. 4/5 and 9/11 are each ratios.
    1. The numerator of one ratio is multiplied by the denominator of the other ratio.
    2. 4 and 9 are numerators. 5 and 11 are denominators.
    1. 4x11=44 and 5x9=45
    2. 44 does not equal 45
    3. The ratios or cross-products must be equal to form a proportion.