Finding the Fourth Proportional to 1,329.59, 1,995.59 and 680.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,329.59 : 1,995.59 = 680.78 : x
2. Step 2: Convert to fraction form
   1,329.59/1,995.59 = 680.78/x
3. Step 3: Cross multiply
   1,329.59x = 1,995.59 × 680.78
4. Step 4: Simplify right side
   1,329.59x = 1,358,557.76
5. Step 5: Solve for x
   x = 1,358,557.76/1,329.59
6. Step 6: Final answer
   x = 1,021.79