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Finding the Fourth Proportional to 13.19, 19.81 and 11.89

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Solution

The fourth proportional to 13.19, 19.81 and 11.89 is: 17.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.19 : 19.81 = 11.89 : x
  2. Step 2: Convert to fraction form
    13.19/19.81 = 11.89/x
  3. Step 3: Cross multiply
    13.19x = 19.81 × 11.89
  4. Step 4: Simplify right side
    13.19x = 235.51
  5. Step 5: Solve for x
    x = 235.51/13.19
  6. Step 6: Final answer
    x = 17.85

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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.