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Finding the Fourth Proportional to 87.13, 129.74 and 84.61

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Solution

The fourth proportional to 87.13, 129.74 and 84.61 is: 125.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.13 : 129.74 = 84.61 : x
  2. Step 2: Convert to fraction form
    87.13/129.74 = 84.61/x
  3. Step 3: Cross multiply
    87.13x = 129.74 × 84.61
  4. Step 4: Simplify right side
    87.13x = 10,977.30
  5. Step 5: Solve for x
    x = 10,977.30/87.13
  6. Step 6: Final answer
    x = 125.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.