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Finding the Fourth Proportional to 639.36, 956.88 and 396.09

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Solution

The fourth proportional to 639.36, 956.88 and 396.09 is: 592.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.36 : 956.88 = 396.09 : x
  2. Step 2: Convert to fraction form
    639.36/956.88 = 396.09/x
  3. Step 3: Cross multiply
    639.36x = 956.88 × 396.09
  4. Step 4: Simplify right side
    639.36x = 379,010.60
  5. Step 5: Solve for x
    x = 379,010.60/639.36
  6. Step 6: Final answer
    x = 592.80

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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.