Finding the Fourth Proportional to 2,638.72, 3,955.02 and 1,340.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.72 : 3,955.02 = 1,340.20 : x
2. Step 2: Convert to fraction form
   2,638.72/3,955.02 = 1,340.20/x
3. Step 3: Cross multiply
   2,638.72x = 3,955.02 × 1,340.20
4. Step 4: Simplify right side
   2,638.72x = 5,300,517.80
5. Step 5: Solve for x
   x = 5,300,517.80/2,638.72
6. Step 6: Final answer
   x = 2,008.75