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Finding the Fourth Proportional to 20.80, 31.26 and 20.62

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Solution

The fourth proportional to 20.80, 31.26 and 20.62 is: 30.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.80 : 31.26 = 20.62 : x
  2. Step 2: Convert to fraction form
    20.80/31.26 = 20.62/x
  3. Step 3: Cross multiply
    20.80x = 31.26 × 20.62
  4. Step 4: Simplify right side
    20.80x = 644.58
  5. Step 5: Solve for x
    x = 644.58/20.80
  6. Step 6: Final answer
    x = 30.99

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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.