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Finding the Fourth Proportional to 138.48, 207.81 and 80.73

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Solution

The fourth proportional to 138.48, 207.81 and 80.73 is: 121.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.48 : 207.81 = 80.73 : x
  2. Step 2: Convert to fraction form
    138.48/207.81 = 80.73/x
  3. Step 3: Cross multiply
    138.48x = 207.81 × 80.73
  4. Step 4: Simplify right side
    138.48x = 16,776.27
  5. Step 5: Solve for x
    x = 16,776.27/138.48
  6. Step 6: Final answer
    x = 121.14

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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.