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Finding the Fourth Proportional to 13.56, 20.30 and 12.30

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Solution

The fourth proportional to 13.56, 20.30 and 12.30 is: 18.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.56 : 20.30 = 12.30 : x
  2. Step 2: Convert to fraction form
    13.56/20.30 = 12.30/x
  3. Step 3: Cross multiply
    13.56x = 20.30 × 12.30
  4. Step 4: Simplify right side
    13.56x = 249.72
  5. Step 5: Solve for x
    x = 249.72/13.56
  6. Step 6: Final answer
    x = 18.42

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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.