Finding the Fourth Proportional to 2,081.28, 3,120.64 and 694.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,081.28 : 3,120.64 = 694.28 : x
2. Step 2: Convert to fraction form
   2,081.28/3,120.64 = 694.28/x
3. Step 3: Cross multiply
   2,081.28x = 3,120.64 × 694.28
4. Step 4: Simplify right side
   2,081.28x = 2,166,597.94
5. Step 5: Solve for x
   x = 2,166,597.94/2,081.28
6. Step 6: Final answer
   x = 1,040.99