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Finding the Fourth Proportional to 87.01, 131.13 and 81.88

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Solution

The fourth proportional to 87.01, 131.13 and 81.88 is: 123.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.01 : 131.13 = 81.88 : x
  2. Step 2: Convert to fraction form
    87.01/131.13 = 81.88/x
  3. Step 3: Cross multiply
    87.01x = 131.13 × 81.88
  4. Step 4: Simplify right side
    87.01x = 10,736.37
  5. Step 5: Solve for x
    x = 10,736.37/87.01
  6. Step 6: Final answer
    x = 123.40

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.