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Finding the Third Proportional to 386.38 and 489.56

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Solution

The third proportional to 386.38 and 489.56 is: 620.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.38 : 489.56 = 489.56 : x
  2. Step 2: Convert to fraction form
    386.38/489.56 = 489.56/x
  3. Step 3: Cross multiply
    386.38x = 489.56 × 489.56
  4. Step 4: Simplify right side
    386.38x = 239,671.44
  5. Step 5: Solve for x
    x = 239,671.44/386.38
  6. Step 6: Final answer
    x = 620.31

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Why These Related Problems?

These problems maintain the same ratio (1.27) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.