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Finding the Fourth Proportional to 439.50, 657.31 and 391.09

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Solution

The fourth proportional to 439.50, 657.31 and 391.09 is: 584.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.50 : 657.31 = 391.09 : x
  2. Step 2: Convert to fraction form
    439.50/657.31 = 391.09/x
  3. Step 3: Cross multiply
    439.50x = 657.31 × 391.09
  4. Step 4: Simplify right side
    439.50x = 257,068.19
  5. Step 5: Solve for x
    x = 257,068.19/439.50
  6. Step 6: Final answer
    x = 584.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.