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Finding the Fourth Proportional to 54.45, 81.72 and 28.80

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Solution

The fourth proportional to 54.45, 81.72 and 28.80 is: 43.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.45 : 81.72 = 28.80 : x
  2. Step 2: Convert to fraction form
    54.45/81.72 = 28.80/x
  3. Step 3: Cross multiply
    54.45x = 81.72 × 28.80
  4. Step 4: Simplify right side
    54.45x = 2,353.54
  5. Step 5: Solve for x
    x = 2,353.54/54.45
  6. Step 6: Final answer
    x = 43.22

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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.