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Finding the Fourth Proportional to 54.66, 81.99 and 21.28

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Solution

The fourth proportional to 54.66, 81.99 and 21.28 is: 31.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.66 : 81.99 = 21.28 : x
  2. Step 2: Convert to fraction form
    54.66/81.99 = 21.28/x
  3. Step 3: Cross multiply
    54.66x = 81.99 × 21.28
  4. Step 4: Simplify right side
    54.66x = 1,744.62
  5. Step 5: Solve for x
    x = 1,744.62/54.66
  6. Step 6: Final answer
    x = 31.92

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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.