Finding the Fourth Proportional to 21,684.21, 29,923.59 and 12,123.51

Step by Step Solution

1. Step 1: Write the proportion equation
   21,684.21 : 29,923.59 = 12,123.51 : x
2. Step 2: Convert to fraction form
   21,684.21/29,923.59 = 12,123.51/x
3. Step 3: Cross multiply
   21,684.21x = 29,923.59 × 12,123.51
4. Step 4: Simplify right side
   21,684.21x = 362,778,942.60
5. Step 5: Solve for x
   x = 362,778,942.60/21,684.21
6. Step 6: Final answer
   x = 16,730.10