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Finding the Fourth Proportional to 81.89, 123.16 and 69.13

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Solution

The fourth proportional to 81.89, 123.16 and 69.13 is: 103.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.89 : 123.16 = 69.13 : x
  2. Step 2: Convert to fraction form
    81.89/123.16 = 69.13/x
  3. Step 3: Cross multiply
    81.89x = 123.16 × 69.13
  4. Step 4: Simplify right side
    81.89x = 8,514.05
  5. Step 5: Solve for x
    x = 8,514.05/81.89
  6. Step 6: Final answer
    x = 103.97

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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.