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Finding the Fourth Proportional to 391.10, 539.66 and 280.94

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Solution

The fourth proportional to 391.10, 539.66 and 280.94 is: 387.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.10 : 539.66 = 280.94 : x
  2. Step 2: Convert to fraction form
    391.10/539.66 = 280.94/x
  3. Step 3: Cross multiply
    391.10x = 539.66 × 280.94
  4. Step 4: Simplify right side
    391.10x = 151,610.08
  5. Step 5: Solve for x
    x = 151,610.08/391.10
  6. Step 6: Final answer
    x = 387.66

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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.