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Finding the Fourth Proportional to 81.11, 121.55 and 54.01

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Solution

The fourth proportional to 81.11, 121.55 and 54.01 is: 80.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.11 : 121.55 = 54.01 : x
  2. Step 2: Convert to fraction form
    81.11/121.55 = 54.01/x
  3. Step 3: Cross multiply
    81.11x = 121.55 × 54.01
  4. Step 4: Simplify right side
    81.11x = 6,564.80
  5. Step 5: Solve for x
    x = 6,564.80/81.11
  6. Step 6: Final answer
    x = 80.93

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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.