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Finding the Fourth Proportional to 12.78, 17.62 and 8.90

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Solution

The fourth proportional to 12.78, 17.62 and 8.90 is: 12.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.78 : 17.62 = 8.90 : x
  2. Step 2: Convert to fraction form
    12.78/17.62 = 8.90/x
  3. Step 3: Cross multiply
    12.78x = 17.62 × 8.90
  4. Step 4: Simplify right side
    12.78x = 156.73
  5. Step 5: Solve for x
    x = 156.73/12.78
  6. Step 6: Final answer
    x = 12.27

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.