Finding the Fourth Proportional to 2,561.38, 3,840.30 and 1,309.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.38 : 3,840.30 = 1,309.55 : x
2. Step 2: Convert to fraction form
   2,561.38/3,840.30 = 1,309.55/x
3. Step 3: Cross multiply
   2,561.38x = 3,840.30 × 1,309.55
4. Step 4: Simplify right side
   2,561.38x = 5,029,045.66
5. Step 5: Solve for x
   x = 5,029,045.66/2,561.38
6. Step 6: Final answer
   x = 1,963.41