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Finding the Fourth Proportional to 254.09, 381.21 and 91.79

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Solution

The fourth proportional to 254.09, 381.21 and 91.79 is: 137.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    254.09 : 381.21 = 91.79 : x
  2. Step 2: Convert to fraction form
    254.09/381.21 = 91.79/x
  3. Step 3: Cross multiply
    254.09x = 381.21 × 91.79
  4. Step 4: Simplify right side
    254.09x = 34,989.36
  5. Step 5: Solve for x
    x = 34,989.36/254.09
  6. Step 6: Final answer
    x = 137.71

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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.