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Finding the Fourth Proportional to 40.12, 60.20 and 20.90

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Solution

The fourth proportional to 40.12, 60.20 and 20.90 is: 31.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.12 : 60.20 = 20.90 : x
  2. Step 2: Convert to fraction form
    40.12/60.20 = 20.90/x
  3. Step 3: Cross multiply
    40.12x = 60.20 × 20.90
  4. Step 4: Simplify right side
    40.12x = 1,258.30
  5. Step 5: Solve for x
    x = 1,258.30/40.12
  6. Step 6: Final answer
    x = 31.37

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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.