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Finding the Fourth Proportional to 85.28, 118.23 and 81.17

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Solution

The fourth proportional to 85.28, 118.23 and 81.17 is: 112.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.28 : 118.23 = 81.17 : x
  2. Step 2: Convert to fraction form
    85.28/118.23 = 81.17/x
  3. Step 3: Cross multiply
    85.28x = 118.23 × 81.17
  4. Step 4: Simplify right side
    85.28x = 9,596.14
  5. Step 5: Solve for x
    x = 9,596.14/85.28
  6. Step 6: Final answer
    x = 112.53

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.