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Finding the Fourth Proportional to 139.76, 209.36 and 105.56

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Solution

The fourth proportional to 139.76, 209.36 and 105.56 is: 158.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.76 : 209.36 = 105.56 : x
  2. Step 2: Convert to fraction form
    139.76/209.36 = 105.56/x
  3. Step 3: Cross multiply
    139.76x = 209.36 × 105.56
  4. Step 4: Simplify right side
    139.76x = 22,098.47
  5. Step 5: Solve for x
    x = 22,098.47/139.76
  6. Step 6: Final answer
    x = 158.12

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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.