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Finding the Fourth Proportional to 20.12, 30.16 and 7.28

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Solution

The fourth proportional to 20.12, 30.16 and 7.28 is: 10.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.12 : 30.16 = 7.28 : x
  2. Step 2: Convert to fraction form
    20.12/30.16 = 7.28/x
  3. Step 3: Cross multiply
    20.12x = 30.16 × 7.28
  4. Step 4: Simplify right side
    20.12x = 219.54
  5. Step 5: Solve for x
    x = 219.54/20.12
  6. Step 6: Final answer
    x = 10.91

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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.