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Finding the Fourth Proportional to 80.64, 111.24 and 54.78

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Solution

The fourth proportional to 80.64, 111.24 and 54.78 is: 75.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.64 : 111.24 = 54.78 : x
  2. Step 2: Convert to fraction form
    80.64/111.24 = 54.78/x
  3. Step 3: Cross multiply
    80.64x = 111.24 × 54.78
  4. Step 4: Simplify right side
    80.64x = 6,093.73
  5. Step 5: Solve for x
    x = 6,093.73/80.64
  6. Step 6: Final answer
    x = 75.57

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.