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Finding the Fourth Proportional to 639.11, 959.29 and 331.18

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Solution

The fourth proportional to 639.11, 959.29 and 331.18 is: 497.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.11 : 959.29 = 331.18 : x
  2. Step 2: Convert to fraction form
    639.11/959.29 = 331.18/x
  3. Step 3: Cross multiply
    639.11x = 959.29 × 331.18
  4. Step 4: Simplify right side
    639.11x = 317,694.44
  5. Step 5: Solve for x
    x = 317,694.44/639.11
  6. Step 6: Final answer
    x = 497.09

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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.