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Finding the Fourth Proportional to 391.14, 539.23 and 280.42

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Solution

The fourth proportional to 391.14, 539.23 and 280.42 is: 386.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.14 : 539.23 = 280.42 : x
  2. Step 2: Convert to fraction form
    391.14/539.23 = 280.42/x
  3. Step 3: Cross multiply
    391.14x = 539.23 × 280.42
  4. Step 4: Simplify right side
    391.14x = 151,210.88
  5. Step 5: Solve for x
    x = 151,210.88/391.14
  6. Step 6: Final answer
    x = 386.59

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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.