Finding the Fourth Proportional to 2,638.35, 3,640.81 and 1,443.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.35 : 3,640.81 = 1,443.31 : x
2. Step 2: Convert to fraction form
   2,638.35/3,640.81 = 1,443.31/x
3. Step 3: Cross multiply
   2,638.35x = 3,640.81 × 1,443.31
4. Step 4: Simplify right side
   2,638.35x = 5,254,817.48
5. Step 5: Solve for x
   x = 5,254,817.48/2,638.35
6. Step 6: Final answer
   x = 1,991.71