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Finding the Third Proportional to 129 and 169

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Solution

The third proportional to 129 and 169 is: 221.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    129 : 169 = 169 : x
  2. Step 2: Convert to fraction form
    129/169 = 169/x
  3. Step 3: Cross multiply
    129x = 169 × 169
  4. Step 4: Simplify right side
    129x = 28,561
  5. Step 5: Solve for x
    x = 28,561/129
  6. Step 6: Final answer
    x = 221.40

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Why These Related Problems?

These problems maintain the same ratio (1.31) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.