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Finding the Third Proportional to 643 and 739

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Solution

The third proportional to 643 and 739 is: 849.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    643 : 739 = 739 : x
  2. Step 2: Convert to fraction form
    643/739 = 739/x
  3. Step 3: Cross multiply
    643x = 739 × 739
  4. Step 4: Simplify right side
    643x = 546,121
  5. Step 5: Solve for x
    x = 546,121/643
  6. Step 6: Final answer
    x = 849.33

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Why These Related Problems?

These problems maintain the same ratio (1.15) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.