Finding the Fourth Proportional to 2,078.86, 3,119.13 and 780.43

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.86 : 3,119.13 = 780.43 : x
2. Step 2: Convert to fraction form
   2,078.86/3,119.13 = 780.43/x
3. Step 3: Cross multiply
   2,078.86x = 3,119.13 × 780.43
4. Step 4: Simplify right side
   2,078.86x = 2,434,262.63
5. Step 5: Solve for x
   x = 2,434,262.63/2,078.86
6. Step 6: Final answer
   x = 1,170.96