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Finding the Fourth Proportional to 639.21, 959.17 and 314.61

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Solution

The fourth proportional to 639.21, 959.17 and 314.61 is: 472.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.21 : 959.17 = 314.61 : x
  2. Step 2: Convert to fraction form
    639.21/959.17 = 314.61/x
  3. Step 3: Cross multiply
    639.21x = 959.17 × 314.61
  4. Step 4: Simplify right side
    639.21x = 301,764.47
  5. Step 5: Solve for x
    x = 301,764.47/639.21
  6. Step 6: Final answer
    x = 472.09

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.