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Finding the Fourth Proportional to 138.36, 190.91 and 80.12

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Solution

The fourth proportional to 138.36, 190.91 and 80.12 is: 110.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.36 : 190.91 = 80.12 : x
  2. Step 2: Convert to fraction form
    138.36/190.91 = 80.12/x
  3. Step 3: Cross multiply
    138.36x = 190.91 × 80.12
  4. Step 4: Simplify right side
    138.36x = 15,295.71
  5. Step 5: Solve for x
    x = 15,295.71/138.36
  6. Step 6: Final answer
    x = 110.55

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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.