Finding the Fourth Proportional to 12,378.16, 17,078.72 and 8,185.60

Step by Step Solution

1. Step 1: Write the proportion equation
   12,378.16 : 17,078.72 = 8,185.60 : x
2. Step 2: Convert to fraction form
   12,378.16/17,078.72 = 8,185.60/x
3. Step 3: Cross multiply
   12,378.16x = 17,078.72 × 8,185.60
4. Step 4: Simplify right side
   12,378.16x = 139,799,570.43
5. Step 5: Solve for x
   x = 139,799,570.43/12,378.16
6. Step 6: Final answer
   x = 11,294.05