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Finding the Third Proportional to 39.87 and 87.21

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Solution

The third proportional to 39.87 and 87.21 is: 190.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.87 : 87.21 = 87.21 : x
  2. Step 2: Convert to fraction form
    39.87/87.21 = 87.21/x
  3. Step 3: Cross multiply
    39.87x = 87.21 × 87.21
  4. Step 4: Simplify right side
    39.87x = 7,605.49
  5. Step 5: Solve for x
    x = 7,605.49/39.87
  6. Step 6: Final answer
    x = 190.77

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Why These Related Problems?

These problems maintain the same ratio (2.19) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.