Finding the Fourth Proportional to 2,643.71, 3,938.21 and 2,555.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,643.71 : 3,938.21 = 2,555.32 : x
2. Step 2: Convert to fraction form
   2,643.71/3,938.21 = 2,555.32/x
3. Step 3: Cross multiply
   2,643.71x = 3,938.21 × 2,555.32
4. Step 4: Simplify right side
   2,643.71x = 10,063,386.78
5. Step 5: Solve for x
   x = 10,063,386.78/2,643.71
6. Step 6: Final answer
   x = 3,806.54