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Finding the Fourth Proportional to 81.89, 122.89 and 43.39

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Solution

The fourth proportional to 81.89, 122.89 and 43.39 is: 65.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.89 : 122.89 = 43.39 : x
  2. Step 2: Convert to fraction form
    81.89/122.89 = 43.39/x
  3. Step 3: Cross multiply
    81.89x = 122.89 × 43.39
  4. Step 4: Simplify right side
    81.89x = 5,331.75
  5. Step 5: Solve for x
    x = 5,331.75/81.89
  6. Step 6: Final answer
    x = 65.11

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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.