Finding the Fourth Proportional to 2,096.78, 3,145.20 and 864.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,096.78 : 3,145.20 = 864.20 : x
2. Step 2: Convert to fraction form
   2,096.78/3,145.20 = 864.20/x
3. Step 3: Cross multiply
   2,096.78x = 3,145.20 × 864.20
4. Step 4: Simplify right side
   2,096.78x = 2,718,081.84
5. Step 5: Solve for x
   x = 2,718,081.84/2,096.78
6. Step 6: Final answer
   x = 1,296.31