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Finding the Fourth Proportional to 137.68, 205.19 and 129.78

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Solution

The fourth proportional to 137.68, 205.19 and 129.78 is: 193.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.68 : 205.19 = 129.78 : x
  2. Step 2: Convert to fraction form
    137.68/205.19 = 129.78/x
  3. Step 3: Cross multiply
    137.68x = 205.19 × 129.78
  4. Step 4: Simplify right side
    137.68x = 26,629.56
  5. Step 5: Solve for x
    x = 26,629.56/137.68
  6. Step 6: Final answer
    x = 193.42

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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.