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Finding the Third Proportional to 728 and 815

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Solution

The third proportional to 728 and 815 is: 912.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    728 : 815 = 815 : x
  2. Step 2: Convert to fraction form
    728/815 = 815/x
  3. Step 3: Cross multiply
    728x = 815 × 815
  4. Step 4: Simplify right side
    728x = 664,225
  5. Step 5: Solve for x
    x = 664,225/728
  6. Step 6: Final answer
    x = 912.40

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Why These Related Problems?

These problems maintain the same ratio (1.12) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.