Finding the Fourth Proportional to 21,141.17, 29,172.71 and 12,641.60

Step by Step Solution

1. Step 1: Write the proportion equation
   21,141.17 : 29,172.71 = 12,641.60 : x
2. Step 2: Convert to fraction form
   21,141.17/29,172.71 = 12,641.60/x
3. Step 3: Cross multiply
   21,141.17x = 29,172.71 × 12,641.60
4. Step 4: Simplify right side
   21,141.17x = 368,789,521.66
5. Step 5: Solve for x
   x = 368,789,521.66/21,141.17
6. Step 6: Final answer
   x = 17,444.14