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Finding the Fourth Proportional to 139.02, 191.71 and 107.87

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Solution

The fourth proportional to 139.02, 191.71 and 107.87 is: 148.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.02 : 191.71 = 107.87 : x
  2. Step 2: Convert to fraction form
    139.02/191.71 = 107.87/x
  3. Step 3: Cross multiply
    139.02x = 191.71 × 107.87
  4. Step 4: Simplify right side
    139.02x = 20,679.76
  5. Step 5: Solve for x
    x = 20,679.76/139.02
  6. Step 6: Final answer
    x = 148.75

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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.