Finding the Fourth Proportional to 21,099.89, 31,656.77 and 8,630.41

Step by Step Solution

1. Step 1: Write the proportion equation
   21,099.89 : 31,656.77 = 8,630.41 : x
2. Step 2: Convert to fraction form
   21,099.89/31,656.77 = 8,630.41/x
3. Step 3: Cross multiply
   21,099.89x = 31,656.77 × 8,630.41
4. Step 4: Simplify right side
   21,099.89x = 273,210,904.38
5. Step 5: Solve for x
   x = 273,210,904.38/21,099.89
6. Step 6: Final answer
   x = 12,948.45