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Finding the Fourth Proportional to 81.10, 122.53 and 80.38

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Solution

The fourth proportional to 81.10, 122.53 and 80.38 is: 121.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.10 : 122.53 = 80.38 : x
  2. Step 2: Convert to fraction form
    81.10/122.53 = 80.38/x
  3. Step 3: Cross multiply
    81.10x = 122.53 × 80.38
  4. Step 4: Simplify right side
    81.10x = 9,847.95
  5. Step 5: Solve for x
    x = 9,847.95/81.10
  6. Step 6: Final answer
    x = 121.44

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.