Finding the Fourth Proportional to 21,111.87, 29,147.94 and 13,561.46

Step by Step Solution

1. Step 1: Write the proportion equation
   21,111.87 : 29,147.94 = 13,561.46 : x
2. Step 2: Convert to fraction form
   21,111.87/29,147.94 = 13,561.46/x
3. Step 3: Cross multiply
   21,111.87x = 29,147.94 × 13,561.46
4. Step 4: Simplify right side
   21,111.87x = 395,288,476.65
5. Step 5: Solve for x
   x = 395,288,476.65/21,111.87
6. Step 6: Final answer
   x = 18,723.52