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Finding the Fourth Proportional to 139.42, 208.11 and 129.13

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Solution

The fourth proportional to 139.42, 208.11 and 129.13 is: 192.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.42 : 208.11 = 129.13 : x
  2. Step 2: Convert to fraction form
    139.42/208.11 = 129.13/x
  3. Step 3: Cross multiply
    139.42x = 208.11 × 129.13
  4. Step 4: Simplify right side
    139.42x = 26,872.20
  5. Step 5: Solve for x
    x = 26,872.20/139.42
  6. Step 6: Final answer
    x = 192.74

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.