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Finding the Fourth Proportional to 20.75, 28.56 and 18.80

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Solution

The fourth proportional to 20.75, 28.56 and 18.80 is: 25.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.75 : 28.56 = 18.80 : x
  2. Step 2: Convert to fraction form
    20.75/28.56 = 18.80/x
  3. Step 3: Cross multiply
    20.75x = 28.56 × 18.80
  4. Step 4: Simplify right side
    20.75x = 536.93
  5. Step 5: Solve for x
    x = 536.93/20.75
  6. Step 6: Final answer
    x = 25.88

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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.