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Finding the Third Proportional to 398.25 and 831.09

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Solution

The third proportional to 398.25 and 831.09 is: 1,734.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.25 : 831.09 = 831.09 : x
  2. Step 2: Convert to fraction form
    398.25/831.09 = 831.09/x
  3. Step 3: Cross multiply
    398.25x = 831.09 × 831.09
  4. Step 4: Simplify right side
    398.25x = 690,716.82
  5. Step 5: Solve for x
    x = 690,716.82/398.25
  6. Step 6: Final answer
    x = 1,734.38

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Why These Related Problems?

These problems maintain the same ratio (2.09) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.