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Finding the Fourth Proportional to 27.78, 38.31 and 20.49

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Solution

The fourth proportional to 27.78, 38.31 and 20.49 is: 28.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.78 : 38.31 = 20.49 : x
  2. Step 2: Convert to fraction form
    27.78/38.31 = 20.49/x
  3. Step 3: Cross multiply
    27.78x = 38.31 × 20.49
  4. Step 4: Simplify right side
    27.78x = 784.97
  5. Step 5: Solve for x
    x = 784.97/27.78
  6. Step 6: Final answer
    x = 28.26

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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.