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Finding the Fourth Proportional to 39.45, 54.39 and 28.55

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Solution

The fourth proportional to 39.45, 54.39 and 28.55 is: 39.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.45 : 54.39 = 28.55 : x
  2. Step 2: Convert to fraction form
    39.45/54.39 = 28.55/x
  3. Step 3: Cross multiply
    39.45x = 54.39 × 28.55
  4. Step 4: Simplify right side
    39.45x = 1,552.56
  5. Step 5: Solve for x
    x = 1,552.56/39.45
  6. Step 6: Final answer
    x = 39.36

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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.