Finding the Fourth Proportional to 21,059.41, 31,561.72 and 8,564.87

Step by Step Solution

1. Step 1: Write the proportion equation
   21,059.41 : 31,561.72 = 8,564.87 : x
2. Step 2: Convert to fraction form
   21,059.41/31,561.72 = 8,564.87/x
3. Step 3: Cross multiply
   21,059.41x = 31,561.72 × 8,564.87
4. Step 4: Simplify right side
   21,059.41x = 270,322,028.78
5. Step 5: Solve for x
   x = 270,322,028.78/21,059.41
6. Step 6: Final answer
   x = 12,836.16