Finding the Fourth Proportional to 21,160.31, 29,191.83 and 13,605.23

Step by Step Solution

1. Step 1: Write the proportion equation
   21,160.31 : 29,191.83 = 13,605.23 : x
2. Step 2: Convert to fraction form
   21,160.31/29,191.83 = 13,605.23/x
3. Step 3: Cross multiply
   21,160.31x = 29,191.83 × 13,605.23
4. Step 4: Simplify right side
   21,160.31x = 397,161,583.23
5. Step 5: Solve for x
   x = 397,161,583.23/21,160.31
6. Step 6: Final answer
   x = 18,769.18