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Finding the Fourth Proportional to 137.05, 189.17 and 81.80

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Solution

The fourth proportional to 137.05, 189.17 and 81.80 is: 112.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.05 : 189.17 = 81.80 : x
  2. Step 2: Convert to fraction form
    137.05/189.17 = 81.80/x
  3. Step 3: Cross multiply
    137.05x = 189.17 × 81.80
  4. Step 4: Simplify right side
    137.05x = 15,474.11
  5. Step 5: Solve for x
    x = 15,474.11/137.05
  6. Step 6: Final answer
    x = 112.91

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.