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Finding the Third Proportional to 399.94 and 820.13

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Solution

The third proportional to 399.94 and 820.13 is: 1,681.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.94 : 820.13 = 820.13 : x
  2. Step 2: Convert to fraction form
    399.94/820.13 = 820.13/x
  3. Step 3: Cross multiply
    399.94x = 820.13 × 820.13
  4. Step 4: Simplify right side
    399.94x = 672,605.02
  5. Step 5: Solve for x
    x = 672,605.02/399.94
  6. Step 6: Final answer
    x = 1,681.78

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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.