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Finding the Third Proportional to 129.09 and 280.55

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Solution

The third proportional to 129.09 and 280.55 is: 609.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.09 : 280.55 = 280.55 : x
  2. Step 2: Convert to fraction form
    129.09/280.55 = 280.55/x
  3. Step 3: Cross multiply
    129.09x = 280.55 × 280.55
  4. Step 4: Simplify right side
    129.09x = 78,706.55
  5. Step 5: Solve for x
    x = 78,706.55/129.09
  6. Step 6: Final answer
    x = 609.69

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Why These Related Problems?

These problems maintain the same ratio (2.17) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.