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Finding the Fourth Proportional to 86.23, 129.39 and 85.96

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Solution

The fourth proportional to 86.23, 129.39 and 85.96 is: 128.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.23 : 129.39 = 85.96 : x
  2. Step 2: Convert to fraction form
    86.23/129.39 = 85.96/x
  3. Step 3: Cross multiply
    86.23x = 129.39 × 85.96
  4. Step 4: Simplify right side
    86.23x = 11,122.36
  5. Step 5: Solve for x
    x = 11,122.36/86.23
  6. Step 6: Final answer
    x = 128.98

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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.