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Finding the Fourth Proportional to 13.11, 19.69 and 12.80

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Solution

The fourth proportional to 13.11, 19.69 and 12.80 is: 19.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.11 : 19.69 = 12.80 : x
  2. Step 2: Convert to fraction form
    13.11/19.69 = 12.80/x
  3. Step 3: Cross multiply
    13.11x = 19.69 × 12.80
  4. Step 4: Simplify right side
    13.11x = 252.12
  5. Step 5: Solve for x
    x = 252.12/13.11
  6. Step 6: Final answer
    x = 19.24

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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.