Finding the Fourth Proportional to 21,698.78, 29,931.81 and 13,727.30

Step by Step Solution

1. Step 1: Write the proportion equation
   21,698.78 : 29,931.81 = 13,727.30 : x
2. Step 2: Convert to fraction form
   21,698.78/29,931.81 = 13,727.30/x
3. Step 3: Cross multiply
   21,698.78x = 29,931.81 × 13,727.30
4. Step 4: Simplify right side
   21,698.78x = 410,882,935.41
5. Step 5: Solve for x
   x = 410,882,935.41/21,698.78
6. Step 6: Final answer
   x = 18,935.76