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Finding the Fourth Proportional to 137.05, 189.14 and 81.81

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Solution

The fourth proportional to 137.05, 189.14 and 81.81 is: 112.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.05 : 189.14 = 81.81 : x
  2. Step 2: Convert to fraction form
    137.05/189.14 = 81.81/x
  3. Step 3: Cross multiply
    137.05x = 189.14 × 81.81
  4. Step 4: Simplify right side
    137.05x = 15,473.13
  5. Step 5: Solve for x
    x = 15,473.13/137.05
  6. Step 6: Final answer
    x = 112.90

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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.