Finding the Fourth Proportional to 1,604.30, 2,213.89 and 905.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,604.30 : 2,213.89 = 905.68 : x
2. Step 2: Convert to fraction form
   1,604.30/2,213.89 = 905.68/x
3. Step 3: Cross multiply
   1,604.30x = 2,213.89 × 905.68
4. Step 4: Simplify right side
   1,604.30x = 2,005,075.90
5. Step 5: Solve for x
   x = 2,005,075.90/1,604.30
6. Step 6: Final answer
   x = 1,249.81