Finding the Fourth Proportional to 15,618.63, 21,553.15 and 8,906.42

Step by Step Solution

1. Step 1: Write the proportion equation
   15,618.63 : 21,553.15 = 8,906.42 : x
2. Step 2: Convert to fraction form
   15,618.63/21,553.15 = 8,906.42/x
3. Step 3: Cross multiply
   15,618.63x = 21,553.15 × 8,906.42
4. Step 4: Simplify right side
   15,618.63x = 191,961,406.22
5. Step 5: Solve for x
   x = 191,961,406.22/15,618.63
6. Step 6: Final answer
   x = 12,290.54