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Finding the Fourth Proportional to 138.92, 208.22 and 77.94

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Solution

The fourth proportional to 138.92, 208.22 and 77.94 is: 116.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.92 : 208.22 = 77.94 : x
  2. Step 2: Convert to fraction form
    138.92/208.22 = 77.94/x
  3. Step 3: Cross multiply
    138.92x = 208.22 × 77.94
  4. Step 4: Simplify right side
    138.92x = 16,228.67
  5. Step 5: Solve for x
    x = 16,228.67/138.92
  6. Step 6: Final answer
    x = 116.82

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.