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Finding the Third Proportional to 121 and 220

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Solution

The third proportional to 121 and 220 is: 400

Step by Step Solution

  1. Step 1: Write the proportion equation
    121 : 220 = 220 : x
  2. Step 2: Convert to fraction form
    121/220 = 220/x
  3. Step 3: Cross multiply
    121x = 220 × 220
  4. Step 4: Simplify right side
    121x = 48,400
  5. Step 5: Solve for x
    x = 48,400/121
  6. Step 6: Final answer
    x = 400

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Why These Related Problems?

These problems maintain the same ratio (1.82) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.