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Finding the Fourth Proportional to 399.12, 550.19 and 280.73

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Solution

The fourth proportional to 399.12, 550.19 and 280.73 is: 386.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.12 : 550.19 = 280.73 : x
  2. Step 2: Convert to fraction form
    399.12/550.19 = 280.73/x
  3. Step 3: Cross multiply
    399.12x = 550.19 × 280.73
  4. Step 4: Simplify right side
    399.12x = 154,454.84
  5. Step 5: Solve for x
    x = 154,454.84/399.12
  6. Step 6: Final answer
    x = 386.99

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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.