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Finding the Third Proportional to 121 and 209

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Solution

The third proportional to 121 and 209 is: 361

Step by Step Solution

  1. Step 1: Write the proportion equation
    121 : 209 = 209 : x
  2. Step 2: Convert to fraction form
    121/209 = 209/x
  3. Step 3: Cross multiply
    121x = 209 × 209
  4. Step 4: Simplify right side
    121x = 43,681
  5. Step 5: Solve for x
    x = 43,681/121
  6. Step 6: Final answer
    x = 361

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Why These Related Problems?

These problems maintain the same ratio (1.73) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.