Finding the Fourth Proportional to 21,078.71, 29,075.88 and 13,906.07

Step by Step Solution

1. Step 1: Write the proportion equation
   21,078.71 : 29,075.88 = 13,906.07 : x
2. Step 2: Convert to fraction form
   21,078.71/29,075.88 = 13,906.07/x
3. Step 3: Cross multiply
   21,078.71x = 29,075.88 × 13,906.07
4. Step 4: Simplify right side
   21,078.71x = 404,331,238.39
5. Step 5: Solve for x
   x = 404,331,238.39/21,078.71
6. Step 6: Final answer
   x = 19,181.97