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Finding the Fourth Proportional to 22.39, 30.90 and 21.09

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Solution

The fourth proportional to 22.39, 30.90 and 21.09 is: 29.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    22.39 : 30.90 = 21.09 : x
  2. Step 2: Convert to fraction form
    22.39/30.90 = 21.09/x
  3. Step 3: Cross multiply
    22.39x = 30.90 × 21.09
  4. Step 4: Simplify right side
    22.39x = 651.68
  5. Step 5: Solve for x
    x = 651.68/22.39
  6. Step 6: Final answer
    x = 29.11

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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.