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Finding the Fourth Proportional to 135.79, 203.38 and 81.57

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Solution

The fourth proportional to 135.79, 203.38 and 81.57 is: 122.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.79 : 203.38 = 81.57 : x
  2. Step 2: Convert to fraction form
    135.79/203.38 = 81.57/x
  3. Step 3: Cross multiply
    135.79x = 203.38 × 81.57
  4. Step 4: Simplify right side
    135.79x = 16,589.30
  5. Step 5: Solve for x
    x = 16,589.30/135.79
  6. Step 6: Final answer
    x = 122.17

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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.