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Finding the Fourth Proportional to 639.91, 958.95 and 331.64

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Solution

The fourth proportional to 639.91, 958.95 and 331.64 is: 496.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.91 : 958.95 = 331.64 : x
  2. Step 2: Convert to fraction form
    639.91/958.95 = 331.64/x
  3. Step 3: Cross multiply
    639.91x = 958.95 × 331.64
  4. Step 4: Simplify right side
    639.91x = 318,021.38
  5. Step 5: Solve for x
    x = 318,021.38/639.91
  6. Step 6: Final answer
    x = 496.98

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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.