Finding the Fourth Proportional to 21,719.18, 29,969.94 and 12,159.59

Step by Step Solution

1. Step 1: Write the proportion equation
   21,719.18 : 29,969.94 = 12,159.59 : x
2. Step 2: Convert to fraction form
   21,719.18/29,969.94 = 12,159.59/x
3. Step 3: Cross multiply
   21,719.18x = 29,969.94 × 12,159.59
4. Step 4: Simplify right side
   21,719.18x = 364,422,182.72
5. Step 5: Solve for x
   x = 364,422,182.72/21,719.18
6. Step 6: Final answer
   x = 16,778.82