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Finding the Fourth Proportional to 609.11, 840.12 and 398.95

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Solution

The fourth proportional to 609.11, 840.12 and 398.95 is: 550.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.11 : 840.12 = 398.95 : x
  2. Step 2: Convert to fraction form
    609.11/840.12 = 398.95/x
  3. Step 3: Cross multiply
    609.11x = 840.12 × 398.95
  4. Step 4: Simplify right side
    609.11x = 335,165.87
  5. Step 5: Solve for x
    x = 335,165.87/609.11
  6. Step 6: Final answer
    x = 550.26

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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.