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Finding the Fourth Proportional to 20.13, 30.21 and 11.56

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Solution

The fourth proportional to 20.13, 30.21 and 11.56 is: 17.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.13 : 30.21 = 11.56 : x
  2. Step 2: Convert to fraction form
    20.13/30.21 = 11.56/x
  3. Step 3: Cross multiply
    20.13x = 30.21 × 11.56
  4. Step 4: Simplify right side
    20.13x = 349.23
  5. Step 5: Solve for x
    x = 349.23/20.13
  6. Step 6: Final answer
    x = 17.35

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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.