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Finding the Fourth Proportional to 86.34, 129.48 and 69.18

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Solution

The fourth proportional to 86.34, 129.48 and 69.18 is: 103.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.34 : 129.48 = 69.18 : x
  2. Step 2: Convert to fraction form
    86.34/129.48 = 69.18/x
  3. Step 3: Cross multiply
    86.34x = 129.48 × 69.18
  4. Step 4: Simplify right side
    86.34x = 8,957.43
  5. Step 5: Solve for x
    x = 8,957.43/86.34
  6. Step 6: Final answer
    x = 103.75

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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.