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Finding the Fourth Proportional to 89.28, 134.57 and 81.18

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Solution

The fourth proportional to 89.28, 134.57 and 81.18 is: 122.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.28 : 134.57 = 81.18 : x
  2. Step 2: Convert to fraction form
    89.28/134.57 = 81.18/x
  3. Step 3: Cross multiply
    89.28x = 134.57 × 81.18
  4. Step 4: Simplify right side
    89.28x = 10,924.60
  5. Step 5: Solve for x
    x = 10,924.60/89.28
  6. Step 6: Final answer
    x = 122.36

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.