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Finding the Third Proportional to 399.38 and 521.44

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Solution

The third proportional to 399.38 and 521.44 is: 680.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.38 : 521.44 = 521.44 : x
  2. Step 2: Convert to fraction form
    399.38/521.44 = 521.44/x
  3. Step 3: Cross multiply
    399.38x = 521.44 × 521.44
  4. Step 4: Simplify right side
    399.38x = 271,897.07
  5. Step 5: Solve for x
    x = 271,897.07/399.38
  6. Step 6: Final answer
    x = 680.81

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Why These Related Problems?

These problems maintain the same ratio (1.31) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.