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Finding the Fourth Proportional to 422.61, 631.20 and 398.91

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Solution

The fourth proportional to 422.61, 631.20 and 398.91 is: 595.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.61 : 631.20 = 398.91 : x
  2. Step 2: Convert to fraction form
    422.61/631.20 = 398.91/x
  3. Step 3: Cross multiply
    422.61x = 631.20 × 398.91
  4. Step 4: Simplify right side
    422.61x = 251,791.99
  5. Step 5: Solve for x
    x = 251,791.99/422.61
  6. Step 6: Final answer
    x = 595.80

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.