Finding the Fourth Proportional to 2,096.31, 3,144.57 and 780.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,096.31 : 3,144.57 = 780.40 : x
2. Step 2: Convert to fraction form
   2,096.31/3,144.57 = 780.40/x
3. Step 3: Cross multiply
   2,096.31x = 3,144.57 × 780.40
4. Step 4: Simplify right side
   2,096.31x = 2,454,022.43
5. Step 5: Solve for x
   x = 2,454,022.43/2,096.31
6. Step 6: Final answer
   x = 1,170.64