Finding the Fourth Proportional to 2,078.94, 3,118.56 and 780.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.94 : 3,118.56 = 780.39 : x
2. Step 2: Convert to fraction form
   2,078.94/3,118.56 = 780.39/x
3. Step 3: Cross multiply
   2,078.94x = 3,118.56 × 780.39
4. Step 4: Simplify right side
   2,078.94x = 2,433,693.04
5. Step 5: Solve for x
   x = 2,433,693.04/2,078.94
6. Step 6: Final answer
   x = 1,170.64