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Finding the Fourth Proportional to 90.97, 136.11 and 85.16

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Solution

The fourth proportional to 90.97, 136.11 and 85.16 is: 127.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.97 : 136.11 = 85.16 : x
  2. Step 2: Convert to fraction form
    90.97/136.11 = 85.16/x
  3. Step 3: Cross multiply
    90.97x = 136.11 × 85.16
  4. Step 4: Simplify right side
    90.97x = 11,591.13
  5. Step 5: Solve for x
    x = 11,591.13/90.97
  6. Step 6: Final answer
    x = 127.42

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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.