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Finding the Third Proportional to 399 and 611

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Solution

The third proportional to 399 and 611 is: 935.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    399 : 611 = 611 : x
  2. Step 2: Convert to fraction form
    399/611 = 611/x
  3. Step 3: Cross multiply
    399x = 611 × 611
  4. Step 4: Simplify right side
    399x = 373,321
  5. Step 5: Solve for x
    x = 373,321/399
  6. Step 6: Final answer
    x = 935.64

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Why These Related Problems?

These problems maintain the same ratio (1.53) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.