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Finding the Fourth Proportional to 639.38, 958.55 and 331.28

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Solution

The fourth proportional to 639.38, 958.55 and 331.28 is: 496.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.38 : 958.55 = 331.28 : x
  2. Step 2: Convert to fraction form
    639.38/958.55 = 331.28/x
  3. Step 3: Cross multiply
    639.38x = 958.55 × 331.28
  4. Step 4: Simplify right side
    639.38x = 317,544.48
  5. Step 5: Solve for x
    x = 317,544.48/639.38
  6. Step 6: Final answer
    x = 496.65

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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.