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Finding the Fourth Proportional to 80.86, 121.34 and 67.12

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Solution

The fourth proportional to 80.86, 121.34 and 67.12 is: 100.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.86 : 121.34 = 67.12 : x
  2. Step 2: Convert to fraction form
    80.86/121.34 = 67.12/x
  3. Step 3: Cross multiply
    80.86x = 121.34 × 67.12
  4. Step 4: Simplify right side
    80.86x = 8,144.34
  5. Step 5: Solve for x
    x = 8,144.34/80.86
  6. Step 6: Final answer
    x = 100.72

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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.