Finding the Fourth Proportional to 21,240.42, 29,312.12 and 11,680.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,240.42 : 29,312.12 = 11,680.72 : x
2. Step 2: Convert to fraction form
   21,240.42/29,312.12 = 11,680.72/x
3. Step 3: Cross multiply
   21,240.42x = 29,312.12 × 11,680.72
4. Step 4: Simplify right side
   21,240.42x = 342,386,666.33
5. Step 5: Solve for x
   x = 342,386,666.33/21,240.42
6. Step 6: Final answer
   x = 16,119.58