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Finding the Fourth Proportional to 84.54, 126.72 and 38.91

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Solution

The fourth proportional to 84.54, 126.72 and 38.91 is: 58.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.54 : 126.72 = 38.91 : x
  2. Step 2: Convert to fraction form
    84.54/126.72 = 38.91/x
  3. Step 3: Cross multiply
    84.54x = 126.72 × 38.91
  4. Step 4: Simplify right side
    84.54x = 4,930.68
  5. Step 5: Solve for x
    x = 4,930.68/84.54
  6. Step 6: Final answer
    x = 58.32

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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.