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Finding the Fourth Proportional to 54.45, 81.71 and 39.21

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Solution

The fourth proportional to 54.45, 81.71 and 39.21 is: 58.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.45 : 81.71 = 39.21 : x
  2. Step 2: Convert to fraction form
    54.45/81.71 = 39.21/x
  3. Step 3: Cross multiply
    54.45x = 81.71 × 39.21
  4. Step 4: Simplify right side
    54.45x = 3,203.65
  5. Step 5: Solve for x
    x = 3,203.65/54.45
  6. Step 6: Final answer
    x = 58.84

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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.