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Finding the Fourth Proportional to 20.77, 28.81 and 20.05

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Solution

The fourth proportional to 20.77, 28.81 and 20.05 is: 27.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.77 : 28.81 = 20.05 : x
  2. Step 2: Convert to fraction form
    20.77/28.81 = 20.05/x
  3. Step 3: Cross multiply
    20.77x = 28.81 × 20.05
  4. Step 4: Simplify right side
    20.77x = 577.64
  5. Step 5: Solve for x
    x = 577.64/20.77
  6. Step 6: Final answer
    x = 27.81

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.