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Finding the Fourth Proportional to 104.12, 155.90 and 85.96

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Solution

The fourth proportional to 104.12, 155.90 and 85.96 is: 128.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    104.12 : 155.90 = 85.96 : x
  2. Step 2: Convert to fraction form
    104.12/155.90 = 85.96/x
  3. Step 3: Cross multiply
    104.12x = 155.90 × 85.96
  4. Step 4: Simplify right side
    104.12x = 13,401.16
  5. Step 5: Solve for x
    x = 13,401.16/104.12
  6. Step 6: Final answer
    x = 128.71

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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.