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Finding the Fourth Proportional to 13.20, 19.69 and 11.31

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Solution

The fourth proportional to 13.20, 19.69 and 11.31 is: 16.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.20 : 19.69 = 11.31 : x
  2. Step 2: Convert to fraction form
    13.20/19.69 = 11.31/x
  3. Step 3: Cross multiply
    13.20x = 19.69 × 11.31
  4. Step 4: Simplify right side
    13.20x = 222.69
  5. Step 5: Solve for x
    x = 222.69/13.20
  6. Step 6: Final answer
    x = 16.87

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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.