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Finding the Third Proportional to 87 and 135

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Solution

The third proportional to 87 and 135 is: 209.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    87 : 135 = 135 : x
  2. Step 2: Convert to fraction form
    87/135 = 135/x
  3. Step 3: Cross multiply
    87x = 135 × 135
  4. Step 4: Simplify right side
    87x = 18,225
  5. Step 5: Solve for x
    x = 18,225/87
  6. Step 6: Final answer
    x = 209.48

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Why These Related Problems?

These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.