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Finding the Fourth Proportional to 81.37, 121.91 and 58.43

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Solution

The fourth proportional to 81.37, 121.91 and 58.43 is: 87.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.37 : 121.91 = 58.43 : x
  2. Step 2: Convert to fraction form
    81.37/121.91 = 58.43/x
  3. Step 3: Cross multiply
    81.37x = 121.91 × 58.43
  4. Step 4: Simplify right side
    81.37x = 7,122.59
  5. Step 5: Solve for x
    x = 7,122.59/81.37
  6. Step 6: Final answer
    x = 87.54

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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.