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Finding the Fourth Proportional to 135.57, 203.31 and 81.39

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Solution

The fourth proportional to 135.57, 203.31 and 81.39 is: 122.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.57 : 203.31 = 81.39 : x
  2. Step 2: Convert to fraction form
    135.57/203.31 = 81.39/x
  3. Step 3: Cross multiply
    135.57x = 203.31 × 81.39
  4. Step 4: Simplify right side
    135.57x = 16,547.40
  5. Step 5: Solve for x
    x = 16,547.40/135.57
  6. Step 6: Final answer
    x = 122.06

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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.