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Finding the Fourth Proportional to 138.50, 208.02 and 115.70

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Solution

The fourth proportional to 138.50, 208.02 and 115.70 is: 173.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.50 : 208.02 = 115.70 : x
  2. Step 2: Convert to fraction form
    138.50/208.02 = 115.70/x
  3. Step 3: Cross multiply
    138.50x = 208.02 × 115.70
  4. Step 4: Simplify right side
    138.50x = 24,067.91
  5. Step 5: Solve for x
    x = 24,067.91/138.50
  6. Step 6: Final answer
    x = 173.78

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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.