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Finding the Fourth Proportional to 86.23, 129.22 and 64.87

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Solution

The fourth proportional to 86.23, 129.22 and 64.87 is: 97.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.23 : 129.22 = 64.87 : x
  2. Step 2: Convert to fraction form
    86.23/129.22 = 64.87/x
  3. Step 3: Cross multiply
    86.23x = 129.22 × 64.87
  4. Step 4: Simplify right side
    86.23x = 8,382.50
  5. Step 5: Solve for x
    x = 8,382.50/86.23
  6. Step 6: Final answer
    x = 97.21

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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.