Finding the Fourth Proportional to 15,513.50, 21,407 and 8,796.98

Step by Step Solution

1. Step 1: Write the proportion equation
   15,513.50 : 21,407 = 8,796.98 : x
2. Step 2: Convert to fraction form
   15,513.50/21,407 = 8,796.98/x
3. Step 3: Cross multiply
   15,513.50x = 21,407 × 8,796.98
4. Step 4: Simplify right side
   15,513.50x = 188,316,950.86
5. Step 5: Solve for x
   x = 188,316,950.86/15,513.50
6. Step 6: Final answer
   x = 12,138.91