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Finding the Fourth Proportional to 422.12, 630.82 and 398.72

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Solution

The fourth proportional to 422.12, 630.82 and 398.72 is: 595.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.12 : 630.82 = 398.72 : x
  2. Step 2: Convert to fraction form
    422.12/630.82 = 398.72/x
  3. Step 3: Cross multiply
    422.12x = 630.82 × 398.72
  4. Step 4: Simplify right side
    422.12x = 251,520.55
  5. Step 5: Solve for x
    x = 251,520.55/422.12
  6. Step 6: Final answer
    x = 595.85

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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.