Finding the Fourth Proportional to 20,389.06, 30,586.42 and 7,238.30

Step by Step Solution

1. Step 1: Write the proportion equation
   20,389.06 : 30,586.42 = 7,238.30 : x
2. Step 2: Convert to fraction form
   20,389.06/30,586.42 = 7,238.30/x
3. Step 3: Cross multiply
   20,389.06x = 30,586.42 × 7,238.30
4. Step 4: Simplify right side
   20,389.06x = 221,393,683.89
5. Step 5: Solve for x
   x = 221,393,683.89/20,389.06
6. Step 6: Final answer
   x = 10,858.45