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Finding the Fourth Proportional to 80.90, 121.20 and 67.14

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Solution

The fourth proportional to 80.90, 121.20 and 67.14 is: 100.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.90 : 121.20 = 67.14 : x
  2. Step 2: Convert to fraction form
    80.90/121.20 = 67.14/x
  3. Step 3: Cross multiply
    80.90x = 121.20 × 67.14
  4. Step 4: Simplify right side
    80.90x = 8,137.37
  5. Step 5: Solve for x
    x = 8,137.37/80.90
  6. Step 6: Final answer
    x = 100.59

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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.