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Finding the Fourth Proportional to 138.38, 207.49 and 61.29

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Solution

The fourth proportional to 138.38, 207.49 and 61.29 is: 91.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.38 : 207.49 = 61.29 : x
  2. Step 2: Convert to fraction form
    138.38/207.49 = 61.29/x
  3. Step 3: Cross multiply
    138.38x = 207.49 × 61.29
  4. Step 4: Simplify right side
    138.38x = 12,717.06
  5. Step 5: Solve for x
    x = 12,717.06/138.38
  6. Step 6: Final answer
    x = 91.90

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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.