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Finding the Fourth Proportional to 138.39, 206.66 and 136.87

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Solution

The fourth proportional to 138.39, 206.66 and 136.87 is: 204.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.39 : 206.66 = 136.87 : x
  2. Step 2: Convert to fraction form
    138.39/206.66 = 136.87/x
  3. Step 3: Cross multiply
    138.39x = 206.66 × 136.87
  4. Step 4: Simplify right side
    138.39x = 28,285.55
  5. Step 5: Solve for x
    x = 28,285.55/138.39
  6. Step 6: Final answer
    x = 204.39

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.