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Finding the Fourth Proportional to 20.23, 30.39 and 12.64

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Solution

The fourth proportional to 20.23, 30.39 and 12.64 is: 18.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.23 : 30.39 = 12.64 : x
  2. Step 2: Convert to fraction form
    20.23/30.39 = 12.64/x
  3. Step 3: Cross multiply
    20.23x = 30.39 × 12.64
  4. Step 4: Simplify right side
    20.23x = 383.98
  5. Step 5: Solve for x
    x = 383.98/20.23
  6. Step 6: Final answer
    x = 18.99

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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.