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Finding the Third Proportional to 128.25 and 200.81

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Solution

The third proportional to 128.25 and 200.81 is: 314.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.25 : 200.81 = 200.81 : x
  2. Step 2: Convert to fraction form
    128.25/200.81 = 200.81/x
  3. Step 3: Cross multiply
    128.25x = 200.81 × 200.81
  4. Step 4: Simplify right side
    128.25x = 40,325.66
  5. Step 5: Solve for x
    x = 40,325.66/128.25
  6. Step 6: Final answer
    x = 314.43

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Why These Related Problems?

These problems maintain the same ratio (1.57) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.