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Finding the Fourth Proportional to 139.43, 192.31 and 129.57

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Solution

The fourth proportional to 139.43, 192.31 and 129.57 is: 178.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.43 : 192.31 = 129.57 : x
  2. Step 2: Convert to fraction form
    139.43/192.31 = 129.57/x
  3. Step 3: Cross multiply
    139.43x = 192.31 × 129.57
  4. Step 4: Simplify right side
    139.43x = 24,917.28
  5. Step 5: Solve for x
    x = 24,917.28/139.43
  6. Step 6: Final answer
    x = 178.71

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.