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Finding the Third Proportional to 218 and 436

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Solution

The third proportional to 218 and 436 is: 872

Step by Step Solution

  1. Step 1: Write the proportion equation
    218 : 436 = 436 : x
  2. Step 2: Convert to fraction form
    218/436 = 436/x
  3. Step 3: Cross multiply
    218x = 436 × 436
  4. Step 4: Simplify right side
    218x = 190,096
  5. Step 5: Solve for x
    x = 190,096/218
  6. Step 6: Final answer
    x = 872

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Why These Related Problems?

These problems maintain the same ratio (2) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.