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Finding the Fourth Proportional to 138.17, 205.90 and 133.81

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Solution

The fourth proportional to 138.17, 205.90 and 133.81 is: 199.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.17 : 205.90 = 133.81 : x
  2. Step 2: Convert to fraction form
    138.17/205.90 = 133.81/x
  3. Step 3: Cross multiply
    138.17x = 205.90 × 133.81
  4. Step 4: Simplify right side
    138.17x = 27,550.63
  5. Step 5: Solve for x
    x = 27,550.63/138.17
  6. Step 6: Final answer
    x = 199.39

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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.