Finding the Fourth Proportional to 2,629.08, 3,943.89 and 780.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,629.08 : 3,943.89 = 780.21 : x
2. Step 2: Convert to fraction form
   2,629.08/3,943.89 = 780.21/x
3. Step 3: Cross multiply
   2,629.08x = 3,943.89 × 780.21
4. Step 4: Simplify right side
   2,629.08x = 3,077,062.42
5. Step 5: Solve for x
   x = 3,077,062.42/2,629.08
6. Step 6: Final answer
   x = 1,170.40