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Finding the Third Proportional to 643 and 693

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Solution

The third proportional to 643 and 693 is: 746.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    643 : 693 = 693 : x
  2. Step 2: Convert to fraction form
    643/693 = 693/x
  3. Step 3: Cross multiply
    643x = 693 × 693
  4. Step 4: Simplify right side
    643x = 480,249
  5. Step 5: Solve for x
    x = 480,249/643
  6. Step 6: Final answer
    x = 746.89

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Why These Related Problems?

These problems maintain the same ratio (1.08) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.