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Finding the Third Proportional to 129 and 315

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Solution

The third proportional to 129 and 315 is: 769.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    129 : 315 = 315 : x
  2. Step 2: Convert to fraction form
    129/315 = 315/x
  3. Step 3: Cross multiply
    129x = 315 × 315
  4. Step 4: Simplify right side
    129x = 99,225
  5. Step 5: Solve for x
    x = 99,225/129
  6. Step 6: Final answer
    x = 769.19

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Why These Related Problems?

These problems maintain the same ratio (2.44) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.