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Finding the Fourth Proportional to 54.79, 82.21 and 20.56

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Solution

The fourth proportional to 54.79, 82.21 and 20.56 is: 30.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.79 : 82.21 = 20.56 : x
  2. Step 2: Convert to fraction form
    54.79/82.21 = 20.56/x
  3. Step 3: Cross multiply
    54.79x = 82.21 × 20.56
  4. Step 4: Simplify right side
    54.79x = 1,690.44
  5. Step 5: Solve for x
    x = 1,690.44/54.79
  6. Step 6: Final answer
    x = 30.85

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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.