Finding the Fourth Proportional to 20,399.31, 30,538.82 and 19,896.30

Step by Step Solution

1. Step 1: Write the proportion equation
   20,399.31 : 30,538.82 = 19,896.30 : x
2. Step 2: Convert to fraction form
   20,399.31/30,538.82 = 19,896.30/x
3. Step 3: Cross multiply
   20,399.31x = 30,538.82 × 19,896.30
4. Step 4: Simplify right side
   20,399.31x = 607,609,574.11
5. Step 5: Solve for x
   x = 607,609,574.11/20,399.31
6. Step 6: Final answer
   x = 29,785.79