Finding the Fourth Proportional to 8,399.84, 12,591.54 and 3,131

Step by Step Solution

1. Step 1: Write the proportion equation
   8,399.84 : 12,591.54 = 3,131 : x
2. Step 2: Convert to fraction form
   8,399.84/12,591.54 = 3,131/x
3. Step 3: Cross multiply
   8,399.84x = 12,591.54 × 3,131
4. Step 4: Simplify right side
   8,399.84x = 39,424,111.74
5. Step 5: Solve for x
   x = 39,424,111.74/8,399.84
6. Step 6: Final answer
   x = 4,693.44