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Finding the Fourth Proportional to 20.12, 27.75 and 12.75

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Solution

The fourth proportional to 20.12, 27.75 and 12.75 is: 17.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.12 : 27.75 = 12.75 : x
  2. Step 2: Convert to fraction form
    20.12/27.75 = 12.75/x
  3. Step 3: Cross multiply
    20.12x = 27.75 × 12.75
  4. Step 4: Simplify right side
    20.12x = 353.66
  5. Step 5: Solve for x
    x = 353.66/20.12
  6. Step 6: Final answer
    x = 17.58

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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.