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Finding the Fourth Proportional to 422.20, 581.34 and 398.17

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Solution

The fourth proportional to 422.20, 581.34 and 398.17 is: 548.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.20 : 581.34 = 398.17 : x
  2. Step 2: Convert to fraction form
    422.20/581.34 = 398.17/x
  3. Step 3: Cross multiply
    422.20x = 581.34 × 398.17
  4. Step 4: Simplify right side
    422.20x = 231,472.15
  5. Step 5: Solve for x
    x = 231,472.15/422.20
  6. Step 6: Final answer
    x = 548.25

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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.