Finding the Fourth Proportional to 21,152.49, 31,728.96 and 8,669.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,152.49 : 31,728.96 = 8,669.31 : x
2. Step 2: Convert to fraction form
   21,152.49/31,728.96 = 8,669.31/x
3. Step 3: Cross multiply
   21,152.49x = 31,728.96 × 8,669.31
4. Step 4: Simplify right side
   21,152.49x = 275,068,190.22
5. Step 5: Solve for x
   x = 275,068,190.22/21,152.49
6. Step 6: Final answer
   x = 13,004.06