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Finding the Fourth Proportional to 138.24, 205.20 and 129.24

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Solution

The fourth proportional to 138.24, 205.20 and 129.24 is: 191.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.24 : 205.20 = 129.24 : x
  2. Step 2: Convert to fraction form
    138.24/205.20 = 129.24/x
  3. Step 3: Cross multiply
    138.24x = 205.20 × 129.24
  4. Step 4: Simplify right side
    138.24x = 26,520.05
  5. Step 5: Solve for x
    x = 26,520.05/138.24
  6. Step 6: Final answer
    x = 191.84

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.