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Finding the Fourth Proportional to 391.62, 539.86 and 308.57

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Solution

The fourth proportional to 391.62, 539.86 and 308.57 is: 425.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.62 : 539.86 = 308.57 : x
  2. Step 2: Convert to fraction form
    391.62/539.86 = 308.57/x
  3. Step 3: Cross multiply
    391.62x = 539.86 × 308.57
  4. Step 4: Simplify right side
    391.62x = 166,581.90
  5. Step 5: Solve for x
    x = 166,581.90/391.62
  6. Step 6: Final answer
    x = 425.36

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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.