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Finding the Third Proportional to 660 and 721

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Solution

The third proportional to 660 and 721 is: 787.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    660 : 721 = 721 : x
  2. Step 2: Convert to fraction form
    660/721 = 721/x
  3. Step 3: Cross multiply
    660x = 721 × 721
  4. Step 4: Simplify right side
    660x = 519,841
  5. Step 5: Solve for x
    x = 519,841/660
  6. Step 6: Final answer
    x = 787.64

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Why These Related Problems?

These problems maintain the same ratio (1.09) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.