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Finding the Fourth Proportional to 20.80, 28.71 and 15.37

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Solution

The fourth proportional to 20.80, 28.71 and 15.37 is: 21.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.80 : 28.71 = 15.37 : x
  2. Step 2: Convert to fraction form
    20.80/28.71 = 15.37/x
  3. Step 3: Cross multiply
    20.80x = 28.71 × 15.37
  4. Step 4: Simplify right side
    20.80x = 441.20
  5. Step 5: Solve for x
    x = 441.20/20.80
  6. Step 6: Final answer
    x = 21.21

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.