Finding the Fourth Proportional to 20,978.04, 31,468.68 and 8,492.16

Step by Step Solution

1. Step 1: Write the proportion equation
   20,978.04 : 31,468.68 = 8,492.16 : x
2. Step 2: Convert to fraction form
   20,978.04/31,468.68 = 8,492.16/x
3. Step 3: Cross multiply
   20,978.04x = 31,468.68 × 8,492.16
4. Step 4: Simplify right side
   20,978.04x = 267,237,065.55
5. Step 5: Solve for x
   x = 267,237,065.55/20,978.04
6. Step 6: Final answer
   x = 12,738.90