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Finding the Fourth Proportional to 20.72, 28.36 and 19.92

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Solution

The fourth proportional to 20.72, 28.36 and 19.92 is: 27.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.72 : 28.36 = 19.92 : x
  2. Step 2: Convert to fraction form
    20.72/28.36 = 19.92/x
  3. Step 3: Cross multiply
    20.72x = 28.36 × 19.92
  4. Step 4: Simplify right side
    20.72x = 564.93
  5. Step 5: Solve for x
    x = 564.93/20.72
  6. Step 6: Final answer
    x = 27.27

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.