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Finding the Fourth Proportional to 139.05, 191.75 and 107.91

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Solution

The fourth proportional to 139.05, 191.75 and 107.91 is: 148.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.05 : 191.75 = 107.91 : x
  2. Step 2: Convert to fraction form
    139.05/191.75 = 107.91/x
  3. Step 3: Cross multiply
    139.05x = 191.75 × 107.91
  4. Step 4: Simplify right side
    139.05x = 20,691.20
  5. Step 5: Solve for x
    x = 20,691.20/139.05
  6. Step 6: Final answer
    x = 148.80

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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.