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Finding the Fourth Proportional to 13.59, 20.36 and 6.81

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Solution

The fourth proportional to 13.59, 20.36 and 6.81 is: 10.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.59 : 20.36 = 6.81 : x
  2. Step 2: Convert to fraction form
    13.59/20.36 = 6.81/x
  3. Step 3: Cross multiply
    13.59x = 20.36 × 6.81
  4. Step 4: Simplify right side
    13.59x = 138.72
  5. Step 5: Solve for x
    x = 138.72/13.59
  6. Step 6: Final answer
    x = 10.21

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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.