Finding the Fourth Proportional to 2,607.40, 3,912.33 and 1,309.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,607.40 : 3,912.33 = 1,309.78 : x
2. Step 2: Convert to fraction form
   2,607.40/3,912.33 = 1,309.78/x
3. Step 3: Cross multiply
   2,607.40x = 3,912.33 × 1,309.78
4. Step 4: Simplify right side
   2,607.40x = 5,124,291.59
5. Step 5: Solve for x
   x = 5,124,291.59/2,607.40
6. Step 6: Final answer
   x = 1,965.29