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Finding the Fourth Proportional to 86.22, 129.18 and 69.88

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Solution

The fourth proportional to 86.22, 129.18 and 69.88 is: 104.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.22 : 129.18 = 69.88 : x
  2. Step 2: Convert to fraction form
    86.22/129.18 = 69.88/x
  3. Step 3: Cross multiply
    86.22x = 129.18 × 69.88
  4. Step 4: Simplify right side
    86.22x = 9,027.10
  5. Step 5: Solve for x
    x = 9,027.10/86.22
  6. Step 6: Final answer
    x = 104.70

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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.