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Finding the Third Proportional to 428,018 and 640,691

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Solution

The third proportional to 428,018 and 640,691 is: 959,036.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    428,018 : 640,691 = 640,691 : x
  2. Step 2: Convert to fraction form
    428,018/640,691 = 640,691/x
  3. Step 3: Cross multiply
    428,018x = 640,691 × 640,691
  4. Step 4: Simplify right side
    428,018x = 410,484,957,481
  5. Step 5: Solve for x
    x = 410,484,957,481/428,018
  6. Step 6: Final answer
    x = 959,036.67

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.