Finding the Fourth Proportional to 21,061.42, 31,564.72 and 8,566.87

Step by Step Solution

1. Step 1: Write the proportion equation
   21,061.42 : 31,564.72 = 8,566.87 : x
2. Step 2: Convert to fraction form
   21,061.42/31,564.72 = 8,566.87/x
3. Step 3: Cross multiply
   21,061.42x = 31,564.72 × 8,566.87
4. Step 4: Simplify right side
   21,061.42x = 270,410,852.83
5. Step 5: Solve for x
   x = 270,410,852.83/21,061.42
6. Step 6: Final answer
   x = 12,839.16