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Finding the Fourth Proportional to 624.34, 861.21 and 391.06

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Solution

The fourth proportional to 624.34, 861.21 and 391.06 is: 539.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    624.34 : 861.21 = 391.06 : x
  2. Step 2: Convert to fraction form
    624.34/861.21 = 391.06/x
  3. Step 3: Cross multiply
    624.34x = 861.21 × 391.06
  4. Step 4: Simplify right side
    624.34x = 336,780.48
  5. Step 5: Solve for x
    x = 336,780.48/624.34
  6. Step 6: Final answer
    x = 539.42

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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.