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Finding the Third Proportional to 390 and 801

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Solution

The third proportional to 390 and 801 is: 1,645.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    390 : 801 = 801 : x
  2. Step 2: Convert to fraction form
    390/801 = 801/x
  3. Step 3: Cross multiply
    390x = 801 × 801
  4. Step 4: Simplify right side
    390x = 641,601
  5. Step 5: Solve for x
    x = 641,601/390
  6. Step 6: Final answer
    x = 1,645.13

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Why These Related Problems?

These problems maintain the same ratio (2.05) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.