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Finding the Third Proportional to 408 and 636

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Solution

The third proportional to 408 and 636 is: 991.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    408 : 636 = 636 : x
  2. Step 2: Convert to fraction form
    408/636 = 636/x
  3. Step 3: Cross multiply
    408x = 636 × 636
  4. Step 4: Simplify right side
    408x = 404,496
  5. Step 5: Solve for x
    x = 404,496/408
  6. Step 6: Final answer
    x = 991.41

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These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.