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Finding the Fourth Proportional to 22.20, 30.24 and 21.72

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Solution

The fourth proportional to 22.20, 30.24 and 21.72 is: 29.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.20 : 30.24 = 21.72 : x
  2. Step 2: Convert to fraction form
    22.20/30.24 = 21.72/x
  3. Step 3: Cross multiply
    22.20x = 30.24 × 21.72
  4. Step 4: Simplify right side
    22.20x = 656.81
  5. Step 5: Solve for x
    x = 656.81/22.20
  6. Step 6: Final answer
    x = 29.59

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.