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Finding the Fourth Proportional to 139.05, 191.88 and 80.82

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Solution

The fourth proportional to 139.05, 191.88 and 80.82 is: 111.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.05 : 191.88 = 80.82 : x
  2. Step 2: Convert to fraction form
    139.05/191.88 = 80.82/x
  3. Step 3: Cross multiply
    139.05x = 191.88 × 80.82
  4. Step 4: Simplify right side
    139.05x = 15,507.74
  5. Step 5: Solve for x
    x = 15,507.74/139.05
  6. Step 6: Final answer
    x = 111.53

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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.