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Finding the Third Proportional to 123 and 261

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Solution

The third proportional to 123 and 261 is: 553.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    123 : 261 = 261 : x
  2. Step 2: Convert to fraction form
    123/261 = 261/x
  3. Step 3: Cross multiply
    123x = 261 × 261
  4. Step 4: Simplify right side
    123x = 68,121
  5. Step 5: Solve for x
    x = 68,121/123
  6. Step 6: Final answer
    x = 553.83

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Why These Related Problems?

These problems maintain the same ratio (2.12) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.