Finding the Fourth Proportional to 21,147.24, 29,181.72 and 11,715

Step by Step Solution

1. Step 1: Write the proportion equation
   21,147.24 : 29,181.72 = 11,715 : x
2. Step 2: Convert to fraction form
   21,147.24/29,181.72 = 11,715/x
3. Step 3: Cross multiply
   21,147.24x = 29,181.72 × 11,715
4. Step 4: Simplify right side
   21,147.24x = 341,863,849.80
5. Step 5: Solve for x
   x = 341,863,849.80/21,147.24
6. Step 6: Final answer
   x = 16,165.88