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Finding the Fourth Proportional to 20.51, 28.31 and 11.77

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Solution

The fourth proportional to 20.51, 28.31 and 11.77 is: 16.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.51 : 28.31 = 11.77 : x
  2. Step 2: Convert to fraction form
    20.51/28.31 = 11.77/x
  3. Step 3: Cross multiply
    20.51x = 28.31 × 11.77
  4. Step 4: Simplify right side
    20.51x = 333.08
  5. Step 5: Solve for x
    x = 333.08/20.51
  6. Step 6: Final answer
    x = 16.24

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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.