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Finding the Fourth Proportional to 129.46, 178.92 and 100.30

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Solution

The fourth proportional to 129.46, 178.92 and 100.30 is: 138.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.46 : 178.92 = 100.30 : x
  2. Step 2: Convert to fraction form
    129.46/178.92 = 100.30/x
  3. Step 3: Cross multiply
    129.46x = 178.92 × 100.30
  4. Step 4: Simplify right side
    129.46x = 17,945.68
  5. Step 5: Solve for x
    x = 17,945.68/129.46
  6. Step 6: Final answer
    x = 138.62

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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.