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Finding the Fourth Proportional to 254.21, 381.17 and 80.85

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Solution

The fourth proportional to 254.21, 381.17 and 80.85 is: 121.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    254.21 : 381.17 = 80.85 : x
  2. Step 2: Convert to fraction form
    254.21/381.17 = 80.85/x
  3. Step 3: Cross multiply
    254.21x = 381.17 × 80.85
  4. Step 4: Simplify right side
    254.21x = 30,815.28
  5. Step 5: Solve for x
    x = 30,815.28/254.21
  6. Step 6: Final answer
    x = 121.22

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.