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Finding the Fourth Proportional to 138.35, 190.86 and 82.31

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Solution

The fourth proportional to 138.35, 190.86 and 82.31 is: 113.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.35 : 190.86 = 82.31 : x
  2. Step 2: Convert to fraction form
    138.35/190.86 = 82.31/x
  3. Step 3: Cross multiply
    138.35x = 190.86 × 82.31
  4. Step 4: Simplify right side
    138.35x = 15,709.69
  5. Step 5: Solve for x
    x = 15,709.69/138.35
  6. Step 6: Final answer
    x = 113.55

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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.