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Finding the Fourth Proportional to 391.58, 539.83 and 280.87

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Solution

The fourth proportional to 391.58, 539.83 and 280.87 is: 387.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.58 : 539.83 = 280.87 : x
  2. Step 2: Convert to fraction form
    391.58/539.83 = 280.87/x
  3. Step 3: Cross multiply
    391.58x = 539.83 × 280.87
  4. Step 4: Simplify right side
    391.58x = 151,622.05
  5. Step 5: Solve for x
    x = 151,622.05/391.58
  6. Step 6: Final answer
    x = 387.21

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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.