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Finding the Fourth Proportional to 54.47, 81.70 and 13.89

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Solution

The fourth proportional to 54.47, 81.70 and 13.89 is: 20.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.47 : 81.70 = 13.89 : x
  2. Step 2: Convert to fraction form
    54.47/81.70 = 13.89/x
  3. Step 3: Cross multiply
    54.47x = 81.70 × 13.89
  4. Step 4: Simplify right side
    54.47x = 1,134.73
  5. Step 5: Solve for x
    x = 1,134.73/54.47
  6. Step 6: Final answer
    x = 20.83

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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.