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Finding the Fourth Proportional to 20.26, 30.40 and 18.76

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Solution

The fourth proportional to 20.26, 30.40 and 18.76 is: 28.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.26 : 30.40 = 18.76 : x
  2. Step 2: Convert to fraction form
    20.26/30.40 = 18.76/x
  3. Step 3: Cross multiply
    20.26x = 30.40 × 18.76
  4. Step 4: Simplify right side
    20.26x = 570.30
  5. Step 5: Solve for x
    x = 570.30/20.26
  6. Step 6: Final answer
    x = 28.15

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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.