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Finding the Fourth Proportional to 54.40, 81.92 and 47.72

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Solution

The fourth proportional to 54.40, 81.92 and 47.72 is: 71.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.40 : 81.92 = 47.72 : x
  2. Step 2: Convert to fraction form
    54.40/81.92 = 47.72/x
  3. Step 3: Cross multiply
    54.40x = 81.92 × 47.72
  4. Step 4: Simplify right side
    54.40x = 3,909.22
  5. Step 5: Solve for x
    x = 3,909.22/54.40
  6. Step 6: Final answer
    x = 71.86

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.