Finding the Fourth Proportional to 21,513, 29,687.94 and 12,081.36

Step by Step Solution

1. Step 1: Write the proportion equation
   21,513 : 29,687.94 = 12,081.36 : x
2. Step 2: Convert to fraction form
   21,513/29,687.94 = 12,081.36/x
3. Step 3: Cross multiply
   21,513x = 29,687.94 × 12,081.36
4. Step 4: Simplify right side
   21,513x = 358,670,690.80
5. Step 5: Solve for x
   x = 358,670,690.80/21,513
6. Step 6: Final answer
   x = 16,672.28