Finding the Fourth Proportional to 8,591.92, 12,870.79 and 5,661.34

Step by Step Solution

1. Step 1: Write the proportion equation
   8,591.92 : 12,870.79 = 5,661.34 : x
2. Step 2: Convert to fraction form
   8,591.92/12,870.79 = 5,661.34/x
3. Step 3: Cross multiply
   8,591.92x = 12,870.79 × 5,661.34
4. Step 4: Simplify right side
   8,591.92x = 72,865,918.26
5. Step 5: Solve for x
   x = 72,865,918.26/8,591.92
6. Step 6: Final answer
   x = 8,480.75