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Finding the Fourth Proportional to 87.69, 121.05 and 69.23

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Solution

The fourth proportional to 87.69, 121.05 and 69.23 is: 95.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.69 : 121.05 = 69.23 : x
  2. Step 2: Convert to fraction form
    87.69/121.05 = 69.23/x
  3. Step 3: Cross multiply
    87.69x = 121.05 × 69.23
  4. Step 4: Simplify right side
    87.69x = 8,380.29
  5. Step 5: Solve for x
    x = 8,380.29/87.69
  6. Step 6: Final answer
    x = 95.57

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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.