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Finding the Third Proportional to 387 and 878

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Solution

The third proportional to 387 and 878 is: 1,991.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    387 : 878 = 878 : x
  2. Step 2: Convert to fraction form
    387/878 = 878/x
  3. Step 3: Cross multiply
    387x = 878 × 878
  4. Step 4: Simplify right side
    387x = 770,884
  5. Step 5: Solve for x
    x = 770,884/387
  6. Step 6: Final answer
    x = 1,991.95

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Why These Related Problems?

These problems maintain the same ratio (2.27) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.