Finding the Fourth Proportional to 8,640.72, 12,955.41 and 3,091.23

Step by Step Solution

1. Step 1: Write the proportion equation
   8,640.72 : 12,955.41 = 3,091.23 : x
2. Step 2: Convert to fraction form
   8,640.72/12,955.41 = 3,091.23/x
3. Step 3: Cross multiply
   8,640.72x = 12,955.41 × 3,091.23
4. Step 4: Simplify right side
   8,640.72x = 40,048,152.05
5. Step 5: Solve for x
   x = 40,048,152.05/8,640.72
6. Step 6: Final answer
   x = 4,634.82