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Finding the Fourth Proportional to 139.31, 208.79 and 106.56

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Solution

The fourth proportional to 139.31, 208.79 and 106.56 is: 159.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.31 : 208.79 = 106.56 : x
  2. Step 2: Convert to fraction form
    139.31/208.79 = 106.56/x
  3. Step 3: Cross multiply
    139.31x = 208.79 × 106.56
  4. Step 4: Simplify right side
    139.31x = 22,248.13
  5. Step 5: Solve for x
    x = 22,248.13/139.31
  6. Step 6: Final answer
    x = 159.71

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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.