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Finding the Third Proportional to 339.75 and 408.75

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Solution

The third proportional to 339.75 and 408.75 is: 491.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    339.75 : 408.75 = 408.75 : x
  2. Step 2: Convert to fraction form
    339.75/408.75 = 408.75/x
  3. Step 3: Cross multiply
    339.75x = 408.75 × 408.75
  4. Step 4: Simplify right side
    339.75x = 167,076.56
  5. Step 5: Solve for x
    x = 167,076.56/339.75
  6. Step 6: Final answer
    x = 491.76

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Why These Related Problems?

These problems maintain the same ratio (1.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.