Finding the Fourth Proportional to 1,385.78, 1,912.40 and 796.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.78 : 1,912.40 = 796.38 : x
2. Step 2: Convert to fraction form
   1,385.78/1,912.40 = 796.38/x
3. Step 3: Cross multiply
   1,385.78x = 1,912.40 × 796.38
4. Step 4: Simplify right side
   1,385.78x = 1,522,997.11
5. Step 5: Solve for x
   x = 1,522,997.11/1,385.78
6. Step 6: Final answer
   x = 1,099.02