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Finding the Fourth Proportional to 128.17, 191.85 and 84.73

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Solution

The fourth proportional to 128.17, 191.85 and 84.73 is: 126.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.17 : 191.85 = 84.73 : x
  2. Step 2: Convert to fraction form
    128.17/191.85 = 84.73/x
  3. Step 3: Cross multiply
    128.17x = 191.85 × 84.73
  4. Step 4: Simplify right side
    128.17x = 16,255.45
  5. Step 5: Solve for x
    x = 16,255.45/128.17
  6. Step 6: Final answer
    x = 126.83

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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.