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Finding the Fourth Proportional to 12.89, 19.18 and 12.85

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Solution

The fourth proportional to 12.89, 19.18 and 12.85 is: 19.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.89 : 19.18 = 12.85 : x
  2. Step 2: Convert to fraction form
    12.89/19.18 = 12.85/x
  3. Step 3: Cross multiply
    12.89x = 19.18 × 12.85
  4. Step 4: Simplify right side
    12.89x = 246.36
  5. Step 5: Solve for x
    x = 246.36/12.89
  6. Step 6: Final answer
    x = 19.11

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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.