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Finding the Fourth Proportional to 609.10, 840.12 and 398.94

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Solution

The fourth proportional to 609.10, 840.12 and 398.94 is: 550.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.10 : 840.12 = 398.94 : x
  2. Step 2: Convert to fraction form
    609.10/840.12 = 398.94/x
  3. Step 3: Cross multiply
    609.10x = 840.12 × 398.94
  4. Step 4: Simplify right side
    609.10x = 335,157.47
  5. Step 5: Solve for x
    x = 335,157.47/609.10
  6. Step 6: Final answer
    x = 550.25

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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.