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Finding the Fourth Proportional to 139.14, 191.85 and 108.12

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Solution

The fourth proportional to 139.14, 191.85 and 108.12 is: 149.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.14 : 191.85 = 108.12 : x
  2. Step 2: Convert to fraction form
    139.14/191.85 = 108.12/x
  3. Step 3: Cross multiply
    139.14x = 191.85 × 108.12
  4. Step 4: Simplify right side
    139.14x = 20,742.82
  5. Step 5: Solve for x
    x = 20,742.82/139.14
  6. Step 6: Final answer
    x = 149.08

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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.