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Finding the Fourth Proportional to 138.09, 206.15 and 119.87

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Solution

The fourth proportional to 138.09, 206.15 and 119.87 is: 178.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.09 : 206.15 = 119.87 : x
  2. Step 2: Convert to fraction form
    138.09/206.15 = 119.87/x
  3. Step 3: Cross multiply
    138.09x = 206.15 × 119.87
  4. Step 4: Simplify right side
    138.09x = 24,711.20
  5. Step 5: Solve for x
    x = 24,711.20/138.09
  6. Step 6: Final answer
    x = 178.95

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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.