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Finding the Fourth Proportional to 129.17, 193.32 and 85.86

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Solution

The fourth proportional to 129.17, 193.32 and 85.86 is: 128.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.17 : 193.32 = 85.86 : x
  2. Step 2: Convert to fraction form
    129.17/193.32 = 85.86/x
  3. Step 3: Cross multiply
    129.17x = 193.32 × 85.86
  4. Step 4: Simplify right side
    129.17x = 16,598.46
  5. Step 5: Solve for x
    x = 16,598.46/129.17
  6. Step 6: Final answer
    x = 128.51

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.