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Finding the Fourth Proportional to 90.73, 135.13 and 85.11

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Solution

The fourth proportional to 90.73, 135.13 and 85.11 is: 126.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.73 : 135.13 = 85.11 : x
  2. Step 2: Convert to fraction form
    90.73/135.13 = 85.11/x
  3. Step 3: Cross multiply
    90.73x = 135.13 × 85.11
  4. Step 4: Simplify right side
    90.73x = 11,500.70
  5. Step 5: Solve for x
    x = 11,500.70/90.73
  6. Step 6: Final answer
    x = 126.76

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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.