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Finding the Fourth Proportional to 54.75, 82.12 and 20.50

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Solution

The fourth proportional to 54.75, 82.12 and 20.50 is: 30.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.75 : 82.12 = 20.50 : x
  2. Step 2: Convert to fraction form
    54.75/82.12 = 20.50/x
  3. Step 3: Cross multiply
    54.75x = 82.12 × 20.50
  4. Step 4: Simplify right side
    54.75x = 1,683.65
  5. Step 5: Solve for x
    x = 1,683.65/54.75
  6. Step 6: Final answer
    x = 30.75

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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.