Finding the Fourth Proportional to 309,019.67, 426,490.35 and 223,256.21

Step by Step Solution

1. Step 1: Write the proportion equation
   309,019.67 : 426,490.35 = 223,256.21 : x
2. Step 2: Convert to fraction form
   309,019.67/426,490.35 = 223,256.21/x
3. Step 3: Cross multiply
   309,019.67x = 426,490.35 × 223,256.21
4. Step 4: Simplify right side
   309,019.67x = 95,216,619,142.57
5. Step 5: Solve for x
   x = 95,216,619,142.57/309,019.67
6. Step 6: Final answer
   x = 308,124.78