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Finding the Fourth Proportional to 391.41, 539.81 and 308.38

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Solution

The fourth proportional to 391.41, 539.81 and 308.38 is: 425.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.41 : 539.81 = 308.38 : x
  2. Step 2: Convert to fraction form
    391.41/539.81 = 308.38/x
  3. Step 3: Cross multiply
    391.41x = 539.81 × 308.38
  4. Step 4: Simplify right side
    391.41x = 166,467.96
  5. Step 5: Solve for x
    x = 166,467.96/391.41
  6. Step 6: Final answer
    x = 425.31

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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.