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Finding the Third Proportional to 339.19 and 687.38

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Solution

The third proportional to 339.19 and 687.38 is: 1,392.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    339.19 : 687.38 = 687.38 : x
  2. Step 2: Convert to fraction form
    339.19/687.38 = 687.38/x
  3. Step 3: Cross multiply
    339.19x = 687.38 × 687.38
  4. Step 4: Simplify right side
    339.19x = 472,484.39
  5. Step 5: Solve for x
    x = 472,484.39/339.19
  6. Step 6: Final answer
    x = 1,392.99

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Why These Related Problems?

These problems maintain the same ratio (2.03) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.