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Finding the Fourth Proportional to 87.48, 131.36 and 85.86

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Solution

The fourth proportional to 87.48, 131.36 and 85.86 is: 128.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.48 : 131.36 = 85.86 : x
  2. Step 2: Convert to fraction form
    87.48/131.36 = 85.86/x
  3. Step 3: Cross multiply
    87.48x = 131.36 × 85.86
  4. Step 4: Simplify right side
    87.48x = 11,278.14
  5. Step 5: Solve for x
    x = 11,278.14/87.48
  6. Step 6: Final answer
    x = 128.92

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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.