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Finding the Fourth Proportional to 12.85, 19.17 and 12.51

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Solution

The fourth proportional to 12.85, 19.17 and 12.51 is: 18.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.85 : 19.17 = 12.51 : x
  2. Step 2: Convert to fraction form
    12.85/19.17 = 12.51/x
  3. Step 3: Cross multiply
    12.85x = 19.17 × 12.51
  4. Step 4: Simplify right side
    12.85x = 239.79
  5. Step 5: Solve for x
    x = 239.79/12.85
  6. Step 6: Final answer
    x = 18.66

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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.