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Finding the Fourth Proportional to 28.28, 42.45 and 20.30

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Solution

The fourth proportional to 28.28, 42.45 and 20.30 is: 30.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.28 : 42.45 = 20.30 : x
  2. Step 2: Convert to fraction form
    28.28/42.45 = 20.30/x
  3. Step 3: Cross multiply
    28.28x = 42.45 × 20.30
  4. Step 4: Simplify right side
    28.28x = 861.74
  5. Step 5: Solve for x
    x = 861.74/28.28
  6. Step 6: Final answer
    x = 30.47

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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.