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Finding the Fourth Proportional to 81.01, 121.33 and 78.85

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Solution

The fourth proportional to 81.01, 121.33 and 78.85 is: 118.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.01 : 121.33 = 78.85 : x
  2. Step 2: Convert to fraction form
    81.01/121.33 = 78.85/x
  3. Step 3: Cross multiply
    81.01x = 121.33 × 78.85
  4. Step 4: Simplify right side
    81.01x = 9,566.87
  5. Step 5: Solve for x
    x = 9,566.87/81.01
  6. Step 6: Final answer
    x = 118.09

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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.