Finding the Fourth Proportional to 20,158.10, 30,233.55 and 12,749.30

Step by Step Solution

1. Step 1: Write the proportion equation
   20,158.10 : 30,233.55 = 12,749.30 : x
2. Step 2: Convert to fraction form
   20,158.10/30,233.55 = 12,749.30/x
3. Step 3: Cross multiply
   20,158.10x = 30,233.55 × 12,749.30
4. Step 4: Simplify right side
   20,158.10x = 385,456,599.02
5. Step 5: Solve for x
   x = 385,456,599.02/20,158.10
6. Step 6: Final answer
   x = 19,121.67