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Finding the Third Proportional to 215 and 381

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Solution

The third proportional to 215 and 381 is: 675.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    215 : 381 = 381 : x
  2. Step 2: Convert to fraction form
    215/381 = 381/x
  3. Step 3: Cross multiply
    215x = 381 × 381
  4. Step 4: Simplify right side
    215x = 145,161
  5. Step 5: Solve for x
    x = 145,161/215
  6. Step 6: Final answer
    x = 675.17

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Why These Related Problems?

These problems maintain the same ratio (1.77) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.