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Finding the Fourth Proportional to 624.28, 861.34 and 391.28

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Solution

The fourth proportional to 624.28, 861.34 and 391.28 is: 539.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    624.28 : 861.34 = 391.28 : x
  2. Step 2: Convert to fraction form
    624.28/861.34 = 391.28/x
  3. Step 3: Cross multiply
    624.28x = 861.34 × 391.28
  4. Step 4: Simplify right side
    624.28x = 337,025.12
  5. Step 5: Solve for x
    x = 337,025.12/624.28
  6. Step 6: Final answer
    x = 539.86

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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.