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Finding the Fourth Proportional to 12.68, 18.90 and 12.66

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Solution

The fourth proportional to 12.68, 18.90 and 12.66 is: 18.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.68 : 18.90 = 12.66 : x
  2. Step 2: Convert to fraction form
    12.68/18.90 = 12.66/x
  3. Step 3: Cross multiply
    12.68x = 18.90 × 12.66
  4. Step 4: Simplify right side
    12.68x = 239.20
  5. Step 5: Solve for x
    x = 239.20/12.68
  6. Step 6: Final answer
    x = 18.87

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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.