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Finding the Fourth Proportional to 129.42, 176.84 and 128.68

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Solution

The fourth proportional to 129.42, 176.84 and 128.68 is: 175.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.42 : 176.84 = 128.68 : x
  2. Step 2: Convert to fraction form
    129.42/176.84 = 128.68/x
  3. Step 3: Cross multiply
    129.42x = 176.84 × 128.68
  4. Step 4: Simplify right side
    129.42x = 22,755.77
  5. Step 5: Solve for x
    x = 22,755.77/129.42
  6. Step 6: Final answer
    x = 175.83

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.