Finding the Fourth Proportional to 21,669.61, 29,903.69 and 12,109.66

Step by Step Solution

1. Step 1: Write the proportion equation
   21,669.61 : 29,903.69 = 12,109.66 : x
2. Step 2: Convert to fraction form
   21,669.61/29,903.69 = 12,109.66/x
3. Step 3: Cross multiply
   21,669.61x = 29,903.69 × 12,109.66
4. Step 4: Simplify right side
   21,669.61x = 362,123,518.65
5. Step 5: Solve for x
   x = 362,123,518.65/21,669.61
6. Step 6: Final answer
   x = 16,711.12