Finding the Fourth Proportional to 12,311.72, 18,470.49 and 3,991.74

Step by Step Solution

1. Step 1: Write the proportion equation
   12,311.72 : 18,470.49 = 3,991.74 : x
2. Step 2: Convert to fraction form
   12,311.72/18,470.49 = 3,991.74/x
3. Step 3: Cross multiply
   12,311.72x = 18,470.49 × 3,991.74
4. Step 4: Simplify right side
   12,311.72x = 73,729,393.75
5. Step 5: Solve for x
   x = 73,729,393.75/12,311.72
6. Step 6: Final answer
   x = 5,988.56