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Finding the Third Proportional to 218 and 487

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Solution

The third proportional to 218 and 487 is: 1,087.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    218 : 487 = 487 : x
  2. Step 2: Convert to fraction form
    218/487 = 487/x
  3. Step 3: Cross multiply
    218x = 487 × 487
  4. Step 4: Simplify right side
    218x = 237,169
  5. Step 5: Solve for x
    x = 237,169/218
  6. Step 6: Final answer
    x = 1,087.93

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Why These Related Problems?

These problems maintain the same ratio (2.23) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.