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Finding the Fourth Proportional to 87.20, 130.18 and 86.96

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Solution

The fourth proportional to 87.20, 130.18 and 86.96 is: 129.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.20 : 130.18 = 86.96 : x
  2. Step 2: Convert to fraction form
    87.20/130.18 = 86.96/x
  3. Step 3: Cross multiply
    87.20x = 130.18 × 86.96
  4. Step 4: Simplify right side
    87.20x = 11,320.45
  5. Step 5: Solve for x
    x = 11,320.45/87.20
  6. Step 6: Final answer
    x = 129.82

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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.