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Finding the Fourth Proportional to 129.60, 178.92 and 103.35

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Solution

The fourth proportional to 129.60, 178.92 and 103.35 is: 142.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.60 : 178.92 = 103.35 : x
  2. Step 2: Convert to fraction form
    129.60/178.92 = 103.35/x
  3. Step 3: Cross multiply
    129.60x = 178.92 × 103.35
  4. Step 4: Simplify right side
    129.60x = 18,491.38
  5. Step 5: Solve for x
    x = 18,491.38/129.60
  6. Step 6: Final answer
    x = 142.68

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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.