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Finding the Fourth Proportional to 28.20, 42.32 and 13.75

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Solution

The fourth proportional to 28.20, 42.32 and 13.75 is: 20.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.20 : 42.32 = 13.75 : x
  2. Step 2: Convert to fraction form
    28.20/42.32 = 13.75/x
  3. Step 3: Cross multiply
    28.20x = 42.32 × 13.75
  4. Step 4: Simplify right side
    28.20x = 581.90
  5. Step 5: Solve for x
    x = 581.90/28.20
  6. Step 6: Final answer
    x = 20.63

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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.