Finding the Fourth Proportional to 1,152.78, 1,591.02 and 680.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.78 : 1,591.02 = 680.69 : x
2. Step 2: Convert to fraction form
   1,152.78/1,591.02 = 680.69/x
3. Step 3: Cross multiply
   1,152.78x = 1,591.02 × 680.69
4. Step 4: Simplify right side
   1,152.78x = 1,082,991.40
5. Step 5: Solve for x
   x = 1,082,991.40/1,152.78
6. Step 6: Final answer
   x = 939.46