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Finding the Fourth Proportional to 640.38, 959.68 and 331.47

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Solution

The fourth proportional to 640.38, 959.68 and 331.47 is: 496.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.38 : 959.68 = 331.47 : x
  2. Step 2: Convert to fraction form
    640.38/959.68 = 331.47/x
  3. Step 3: Cross multiply
    640.38x = 959.68 × 331.47
  4. Step 4: Simplify right side
    640.38x = 318,105.13
  5. Step 5: Solve for x
    x = 318,105.13/640.38
  6. Step 6: Final answer
    x = 496.74

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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.