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Finding the Fourth Proportional to 138.05, 206.75 and 83.87

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Solution

The fourth proportional to 138.05, 206.75 and 83.87 is: 125.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.05 : 206.75 = 83.87 : x
  2. Step 2: Convert to fraction form
    138.05/206.75 = 83.87/x
  3. Step 3: Cross multiply
    138.05x = 206.75 × 83.87
  4. Step 4: Simplify right side
    138.05x = 17,339.30
  5. Step 5: Solve for x
    x = 17,339.30/138.05
  6. Step 6: Final answer
    x = 125.61

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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.