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Finding the Fourth Proportional to 87.93, 121.16 and 67.21

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Solution

The fourth proportional to 87.93, 121.16 and 67.21 is: 92.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.93 : 121.16 = 67.21 : x
  2. Step 2: Convert to fraction form
    87.93/121.16 = 67.21/x
  3. Step 3: Cross multiply
    87.93x = 121.16 × 67.21
  4. Step 4: Simplify right side
    87.93x = 8,143.03
  5. Step 5: Solve for x
    x = 8,143.03/87.93
  6. Step 6: Final answer
    x = 92.61

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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.