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Finding the Fourth Proportional to 391.66, 539.76 and 280.96

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Solution

The fourth proportional to 391.66, 539.76 and 280.96 is: 387.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.66 : 539.76 = 280.96 : x
  2. Step 2: Convert to fraction form
    391.66/539.76 = 280.96/x
  3. Step 3: Cross multiply
    391.66x = 539.76 × 280.96
  4. Step 4: Simplify right side
    391.66x = 151,650.97
  5. Step 5: Solve for x
    x = 151,650.97/391.66
  6. Step 6: Final answer
    x = 387.20

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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.