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Finding the Fourth Proportional to 22.05, 30.36 and 20.91

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Solution

The fourth proportional to 22.05, 30.36 and 20.91 is: 28.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.05 : 30.36 = 20.91 : x
  2. Step 2: Convert to fraction form
    22.05/30.36 = 20.91/x
  3. Step 3: Cross multiply
    22.05x = 30.36 × 20.91
  4. Step 4: Simplify right side
    22.05x = 634.82
  5. Step 5: Solve for x
    x = 634.82/22.05
  6. Step 6: Final answer
    x = 28.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.