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Finding the Fourth Proportional to 86.32, 129.25 and 82.05

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Solution

The fourth proportional to 86.32, 129.25 and 82.05 is: 122.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.32 : 129.25 = 82.05 : x
  2. Step 2: Convert to fraction form
    86.32/129.25 = 82.05/x
  3. Step 3: Cross multiply
    86.32x = 129.25 × 82.05
  4. Step 4: Simplify right side
    86.32x = 10,604.96
  5. Step 5: Solve for x
    x = 10,604.96/86.32
  6. Step 6: Final answer
    x = 122.86

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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.