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Finding the Fourth Proportional to 138.32, 190.86 and 80.09

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Solution

The fourth proportional to 138.32, 190.86 and 80.09 is: 110.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.32 : 190.86 = 80.09 : x
  2. Step 2: Convert to fraction form
    138.32/190.86 = 80.09/x
  3. Step 3: Cross multiply
    138.32x = 190.86 × 80.09
  4. Step 4: Simplify right side
    138.32x = 15,285.98
  5. Step 5: Solve for x
    x = 15,285.98/138.32
  6. Step 6: Final answer
    x = 110.51

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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.