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Finding the Fourth Proportional to 13.59, 20.28 and 12.81

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Solution

The fourth proportional to 13.59, 20.28 and 12.81 is: 19.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.59 : 20.28 = 12.81 : x
  2. Step 2: Convert to fraction form
    13.59/20.28 = 12.81/x
  3. Step 3: Cross multiply
    13.59x = 20.28 × 12.81
  4. Step 4: Simplify right side
    13.59x = 259.79
  5. Step 5: Solve for x
    x = 259.79/13.59
  6. Step 6: Final answer
    x = 19.12

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.