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Finding the Fourth Proportional to 391.14, 539.73 and 280.85

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Solution

The fourth proportional to 391.14, 539.73 and 280.85 is: 387.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.14 : 539.73 = 280.85 : x
  2. Step 2: Convert to fraction form
    391.14/539.73 = 280.85/x
  3. Step 3: Cross multiply
    391.14x = 539.73 × 280.85
  4. Step 4: Simplify right side
    391.14x = 151,580.47
  5. Step 5: Solve for x
    x = 151,580.47/391.14
  6. Step 6: Final answer
    x = 387.54

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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.