Finding the Fourth Proportional to 21,111.50, 29,132.56 and 11,680.07

Step by Step Solution

1. Step 1: Write the proportion equation
   21,111.50 : 29,132.56 = 11,680.07 : x
2. Step 2: Convert to fraction form
   21,111.50/29,132.56 = 11,680.07/x
3. Step 3: Cross multiply
   21,111.50x = 29,132.56 × 11,680.07
4. Step 4: Simplify right side
   21,111.50x = 340,270,209.02
5. Step 5: Solve for x
   x = 340,270,209.02/21,111.50
6. Step 6: Final answer
   x = 16,117.76