Finding the Fourth Proportional to 21,145.43, 29,174.06 and 12,191.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,145.43 : 29,174.06 = 12,191.72 : x
2. Step 2: Convert to fraction form
   21,145.43/29,174.06 = 12,191.72/x
3. Step 3: Cross multiply
   21,145.43x = 29,174.06 × 12,191.72
4. Step 4: Simplify right side
   21,145.43x = 355,681,763.95
5. Step 5: Solve for x
   x = 355,681,763.95/21,145.43
6. Step 6: Final answer
   x = 16,820.74