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Finding the Fourth Proportional to 38.05, 52.51 and 20.80

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Solution

The fourth proportional to 38.05, 52.51 and 20.80 is: 28.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.05 : 52.51 = 20.80 : x
  2. Step 2: Convert to fraction form
    38.05/52.51 = 20.80/x
  3. Step 3: Cross multiply
    38.05x = 52.51 × 20.80
  4. Step 4: Simplify right side
    38.05x = 1,091.97
  5. Step 5: Solve for x
    x = 1,091.97/38.05
  6. Step 6: Final answer
    x = 28.70

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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.