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Finding the Fourth Proportional to 39.08, 54.31 and 38.64

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Solution

The fourth proportional to 39.08, 54.31 and 38.64 is: 53.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.08 : 54.31 = 38.64 : x
  2. Step 2: Convert to fraction form
    39.08/54.31 = 38.64/x
  3. Step 3: Cross multiply
    39.08x = 54.31 × 38.64
  4. Step 4: Simplify right side
    39.08x = 2,098.54
  5. Step 5: Solve for x
    x = 2,098.54/39.08
  6. Step 6: Final answer
    x = 53.70

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.