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Finding the Fourth Proportional to 87.96, 131.88 and 39.87

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Solution

The fourth proportional to 87.96, 131.88 and 39.87 is: 59.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.96 : 131.88 = 39.87 : x
  2. Step 2: Convert to fraction form
    87.96/131.88 = 39.87/x
  3. Step 3: Cross multiply
    87.96x = 131.88 × 39.87
  4. Step 4: Simplify right side
    87.96x = 5,258.06
  5. Step 5: Solve for x
    x = 5,258.06/87.96
  6. Step 6: Final answer
    x = 59.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.