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Finding the Fourth Proportional to 84.54, 127.56 and 81.38

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Solution

The fourth proportional to 84.54, 127.56 and 81.38 is: 122.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.54 : 127.56 = 81.38 : x
  2. Step 2: Convert to fraction form
    84.54/127.56 = 81.38/x
  3. Step 3: Cross multiply
    84.54x = 127.56 × 81.38
  4. Step 4: Simplify right side
    84.54x = 10,380.20
  5. Step 5: Solve for x
    x = 10,380.20/84.54
  6. Step 6: Final answer
    x = 122.78

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.