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Finding the Third Proportional to 399 and 699

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Solution

The third proportional to 399 and 699 is: 1,224.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    399 : 699 = 699 : x
  2. Step 2: Convert to fraction form
    399/699 = 699/x
  3. Step 3: Cross multiply
    399x = 699 × 699
  4. Step 4: Simplify right side
    399x = 488,601
  5. Step 5: Solve for x
    x = 488,601/399
  6. Step 6: Final answer
    x = 1,224.56

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Why These Related Problems?

These problems maintain the same ratio (1.75) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.