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Finding the Fourth Proportional to 30.82, 42.56 and 28.22

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Solution

The fourth proportional to 30.82, 42.56 and 28.22 is: 38.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.82 : 42.56 = 28.22 : x
  2. Step 2: Convert to fraction form
    30.82/42.56 = 28.22/x
  3. Step 3: Cross multiply
    30.82x = 42.56 × 28.22
  4. Step 4: Simplify right side
    30.82x = 1,201.04
  5. Step 5: Solve for x
    x = 1,201.04/30.82
  6. Step 6: Final answer
    x = 38.97

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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.