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Finding the Fourth Proportional to 138.60, 206.89 and 129.48

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Solution

The fourth proportional to 138.60, 206.89 and 129.48 is: 193.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.60 : 206.89 = 129.48 : x
  2. Step 2: Convert to fraction form
    138.60/206.89 = 129.48/x
  3. Step 3: Cross multiply
    138.60x = 206.89 × 129.48
  4. Step 4: Simplify right side
    138.60x = 26,787.79
  5. Step 5: Solve for x
    x = 26,787.79/138.60
  6. Step 6: Final answer
    x = 193.27

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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.