Finding the Fourth Proportional to 2,559.63, 3,840.81 and 1,390.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,559.63 : 3,840.81 = 1,390.50 : x
2. Step 2: Convert to fraction form
   2,559.63/3,840.81 = 1,390.50/x
3. Step 3: Cross multiply
   2,559.63x = 3,840.81 × 1,390.50
4. Step 4: Simplify right side
   2,559.63x = 5,340,646.31
5. Step 5: Solve for x
   x = 5,340,646.31/2,559.63
6. Step 6: Final answer
   x = 2,086.49