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Finding the Fourth Proportional to 640.38, 958.78 and 331.57

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Solution

The fourth proportional to 640.38, 958.78 and 331.57 is: 496.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.38 : 958.78 = 331.57 : x
  2. Step 2: Convert to fraction form
    640.38/958.78 = 331.57/x
  3. Step 3: Cross multiply
    640.38x = 958.78 × 331.57
  4. Step 4: Simplify right side
    640.38x = 317,902.68
  5. Step 5: Solve for x
    x = 317,902.68/640.38
  6. Step 6: Final answer
    x = 496.43

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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.