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Finding the Third Proportional to 422 and 642

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Solution

The third proportional to 422 and 642 is: 976.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    422 : 642 = 642 : x
  2. Step 2: Convert to fraction form
    422/642 = 642/x
  3. Step 3: Cross multiply
    422x = 642 × 642
  4. Step 4: Simplify right side
    422x = 412,164
  5. Step 5: Solve for x
    x = 412,164/422
  6. Step 6: Final answer
    x = 976.69

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These problems maintain the same ratio (1.52) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.