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Finding the Fourth Proportional to 391.29, 540.12 and 308.77

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Solution

The fourth proportional to 391.29, 540.12 and 308.77 is: 426.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.29 : 540.12 = 308.77 : x
  2. Step 2: Convert to fraction form
    391.29/540.12 = 308.77/x
  3. Step 3: Cross multiply
    391.29x = 540.12 × 308.77
  4. Step 4: Simplify right side
    391.29x = 166,772.85
  5. Step 5: Solve for x
    x = 166,772.85/391.29
  6. Step 6: Final answer
    x = 426.21

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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.