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Finding the Fourth Proportional to 13.65, 18.91 and 12.69

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Solution

The fourth proportional to 13.65, 18.91 and 12.69 is: 17.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.65 : 18.91 = 12.69 : x
  2. Step 2: Convert to fraction form
    13.65/18.91 = 12.69/x
  3. Step 3: Cross multiply
    13.65x = 18.91 × 12.69
  4. Step 4: Simplify right side
    13.65x = 239.97
  5. Step 5: Solve for x
    x = 239.97/13.65
  6. Step 6: Final answer
    x = 17.58

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.