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Finding the Fourth Proportional to 20.50, 28.28 and 12.31

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Solution

The fourth proportional to 20.50, 28.28 and 12.31 is: 16.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.50 : 28.28 = 12.31 : x
  2. Step 2: Convert to fraction form
    20.50/28.28 = 12.31/x
  3. Step 3: Cross multiply
    20.50x = 28.28 × 12.31
  4. Step 4: Simplify right side
    20.50x = 347.99
  5. Step 5: Solve for x
    x = 347.99/20.50
  6. Step 6: Final answer
    x = 16.98

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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.