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Finding the Third Proportional to 129.09 and 200.81

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Solution

The third proportional to 129.09 and 200.81 is: 312.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.09 : 200.81 = 200.81 : x
  2. Step 2: Convert to fraction form
    129.09/200.81 = 200.81/x
  3. Step 3: Cross multiply
    129.09x = 200.81 × 200.81
  4. Step 4: Simplify right side
    129.09x = 40,325.66
  5. Step 5: Solve for x
    x = 40,325.66/129.09
  6. Step 6: Final answer
    x = 312.38

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Why These Related Problems?

These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.