Finding the Fourth Proportional to 804.69, 1,200.60 and 768.78

Step by Step Solution

1. Step 1: Write the proportion equation
   804.69 : 1,200.60 = 768.78 : x
2. Step 2: Convert to fraction form
   804.69/1,200.60 = 768.78/x
3. Step 3: Cross multiply
   804.69x = 1,200.60 × 768.78
4. Step 4: Simplify right side
   804.69x = 922,997.27
5. Step 5: Solve for x
   x = 922,997.27/804.69
6. Step 6: Final answer
   x = 1,147.02