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Finding the Fourth Proportional to 391.13, 540.07 and 280.87

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Solution

The fourth proportional to 391.13, 540.07 and 280.87 is: 387.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.13 : 540.07 = 280.87 : x
  2. Step 2: Convert to fraction form
    391.13/540.07 = 280.87/x
  3. Step 3: Cross multiply
    391.13x = 540.07 × 280.87
  4. Step 4: Simplify right side
    391.13x = 151,687.41
  5. Step 5: Solve for x
    x = 151,687.41/391.13
  6. Step 6: Final answer
    x = 387.82

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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.