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Finding the Fourth Proportional to 87.36, 131.26 and 81.89

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Solution

The fourth proportional to 87.36, 131.26 and 81.89 is: 123.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.36 : 131.26 = 81.89 : x
  2. Step 2: Convert to fraction form
    87.36/131.26 = 81.89/x
  3. Step 3: Cross multiply
    87.36x = 131.26 × 81.89
  4. Step 4: Simplify right side
    87.36x = 10,748.88
  5. Step 5: Solve for x
    x = 10,748.88/87.36
  6. Step 6: Final answer
    x = 123.04

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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.