Finding the Fourth Proportional to 309,258, 426,776.10 and 188,399.25

Step by Step Solution

1. Step 1: Write the proportion equation
   309,258 : 426,776.10 = 188,399.25 : x
2. Step 2: Convert to fraction form
   309,258/426,776.10 = 188,399.25/x
3. Step 3: Cross multiply
   309,258x = 426,776.10 × 188,399.25
4. Step 4: Simplify right side
   309,258x = 80,404,297,628.92
5. Step 5: Solve for x
   x = 80,404,297,628.92/309,258
6. Step 6: Final answer
   x = 259,991.00