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Finding the Fourth Proportional to 87.65, 131.39 and 80.83

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Solution

The fourth proportional to 87.65, 131.39 and 80.83 is: 121.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.65 : 131.39 = 80.83 : x
  2. Step 2: Convert to fraction form
    87.65/131.39 = 80.83/x
  3. Step 3: Cross multiply
    87.65x = 131.39 × 80.83
  4. Step 4: Simplify right side
    87.65x = 10,619.19
  5. Step 5: Solve for x
    x = 10,619.19/87.65
  6. Step 6: Final answer
    x = 121.15

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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.