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Finding the Fourth Proportional to 129.81, 179.24 and 100.86

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Solution

The fourth proportional to 129.81, 179.24 and 100.86 is: 139.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.81 : 179.24 = 100.86 : x
  2. Step 2: Convert to fraction form
    129.81/179.24 = 100.86/x
  3. Step 3: Cross multiply
    129.81x = 179.24 × 100.86
  4. Step 4: Simplify right side
    129.81x = 18,078.15
  5. Step 5: Solve for x
    x = 18,078.15/129.81
  6. Step 6: Final answer
    x = 139.27

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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.