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Finding the Fourth Proportional to 89.12, 132.78 and 85.18

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Solution

The fourth proportional to 89.12, 132.78 and 85.18 is: 126.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.12 : 132.78 = 85.18 : x
  2. Step 2: Convert to fraction form
    89.12/132.78 = 85.18/x
  3. Step 3: Cross multiply
    89.12x = 132.78 × 85.18
  4. Step 4: Simplify right side
    89.12x = 11,310.53
  5. Step 5: Solve for x
    x = 11,310.53/89.12
  6. Step 6: Final answer
    x = 126.92

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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.