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Finding the Third Proportional to 217 and 381

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Solution

The third proportional to 217 and 381 is: 668.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    217 : 381 = 381 : x
  2. Step 2: Convert to fraction form
    217/381 = 381/x
  3. Step 3: Cross multiply
    217x = 381 × 381
  4. Step 4: Simplify right side
    217x = 145,161
  5. Step 5: Solve for x
    x = 145,161/217
  6. Step 6: Final answer
    x = 668.94

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Why These Related Problems?

These problems maintain the same ratio (1.76) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.