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Finding the Fourth Proportional to 87.38, 120.34 and 72.69

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Solution

The fourth proportional to 87.38, 120.34 and 72.69 is: 100.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.38 : 120.34 = 72.69 : x
  2. Step 2: Convert to fraction form
    87.38/120.34 = 72.69/x
  3. Step 3: Cross multiply
    87.38x = 120.34 × 72.69
  4. Step 4: Simplify right side
    87.38x = 8,747.15
  5. Step 5: Solve for x
    x = 8,747.15/87.38
  6. Step 6: Final answer
    x = 100.10

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.