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Finding the Fourth Proportional to 80.95, 121.43 and 55.21

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Solution

The fourth proportional to 80.95, 121.43 and 55.21 is: 82.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.95 : 121.43 = 55.21 : x
  2. Step 2: Convert to fraction form
    80.95/121.43 = 55.21/x
  3. Step 3: Cross multiply
    80.95x = 121.43 × 55.21
  4. Step 4: Simplify right side
    80.95x = 6,704.15
  5. Step 5: Solve for x
    x = 6,704.15/80.95
  6. Step 6: Final answer
    x = 82.82

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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.