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Finding the Fourth Proportional to 139.79, 209.19 and 120.76

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Solution

The fourth proportional to 139.79, 209.19 and 120.76 is: 180.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.79 : 209.19 = 120.76 : x
  2. Step 2: Convert to fraction form
    139.79/209.19 = 120.76/x
  3. Step 3: Cross multiply
    139.79x = 209.19 × 120.76
  4. Step 4: Simplify right side
    139.79x = 25,261.78
  5. Step 5: Solve for x
    x = 25,261.78/139.79
  6. Step 6: Final answer
    x = 180.71

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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.