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Finding the Fourth Proportional to 20.74, 31.12 and 12.74

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Solution

The fourth proportional to 20.74, 31.12 and 12.74 is: 19.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.74 : 31.12 = 12.74 : x
  2. Step 2: Convert to fraction form
    20.74/31.12 = 12.74/x
  3. Step 3: Cross multiply
    20.74x = 31.12 × 12.74
  4. Step 4: Simplify right side
    20.74x = 396.47
  5. Step 5: Solve for x
    x = 396.47/20.74
  6. Step 6: Final answer
    x = 19.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.