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Finding the Fourth Proportional to 81.58, 122.49 and 80.22

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Solution

The fourth proportional to 81.58, 122.49 and 80.22 is: 120.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.58 : 122.49 = 80.22 : x
  2. Step 2: Convert to fraction form
    81.58/122.49 = 80.22/x
  3. Step 3: Cross multiply
    81.58x = 122.49 × 80.22
  4. Step 4: Simplify right side
    81.58x = 9,826.15
  5. Step 5: Solve for x
    x = 9,826.15/81.58
  6. Step 6: Final answer
    x = 120.45

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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.