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Finding the Fourth Proportional to 138,276, 207,414 and 39,780

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Solution

The fourth proportional to 138,276, 207,414 and 39,780 is: 59,670

Step by Step Solution

  1. Step 1: Write the proportion equation
    138,276 : 207,414 = 39,780 : x
  2. Step 2: Convert to fraction form
    138,276/207,414 = 39,780/x
  3. Step 3: Cross multiply
    138,276x = 207,414 × 39,780
  4. Step 4: Simplify right side
    138,276x = 8,250,928,920
  5. Step 5: Solve for x
    x = 8,250,928,920/138,276
  6. Step 6: Final answer
    x = 59,670

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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.