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Finding the Fourth Proportional to 39.87, 54.96 and 28.22

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Solution

The fourth proportional to 39.87, 54.96 and 28.22 is: 38.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.87 : 54.96 = 28.22 : x
  2. Step 2: Convert to fraction form
    39.87/54.96 = 28.22/x
  3. Step 3: Cross multiply
    39.87x = 54.96 × 28.22
  4. Step 4: Simplify right side
    39.87x = 1,550.97
  5. Step 5: Solve for x
    x = 1,550.97/39.87
  6. Step 6: Final answer
    x = 38.91

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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.