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Finding the Fourth Proportional to 138.94, 191.81 and 107.79

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Solution

The fourth proportional to 138.94, 191.81 and 107.79 is: 148.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.94 : 191.81 = 107.79 : x
  2. Step 2: Convert to fraction form
    138.94/191.81 = 107.79/x
  3. Step 3: Cross multiply
    138.94x = 191.81 × 107.79
  4. Step 4: Simplify right side
    138.94x = 20,675.20
  5. Step 5: Solve for x
    x = 20,675.20/138.94
  6. Step 6: Final answer
    x = 148.81

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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.