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Finding the Fourth Proportional to 28.13, 42.14 and 20.89

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Solution

The fourth proportional to 28.13, 42.14 and 20.89 is: 31.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.13 : 42.14 = 20.89 : x
  2. Step 2: Convert to fraction form
    28.13/42.14 = 20.89/x
  3. Step 3: Cross multiply
    28.13x = 42.14 × 20.89
  4. Step 4: Simplify right side
    28.13x = 880.30
  5. Step 5: Solve for x
    x = 880.30/28.13
  6. Step 6: Final answer
    x = 31.29

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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.