Finding the Fourth Proportional to 1,082.69, 1,493.42 and 640.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,082.69 : 1,493.42 = 640.28 : x
2. Step 2: Convert to fraction form
   1,082.69/1,493.42 = 640.28/x
3. Step 3: Cross multiply
   1,082.69x = 1,493.42 × 640.28
4. Step 4: Simplify right side
   1,082.69x = 956,206.96
5. Step 5: Solve for x
   x = 956,206.96/1,082.69
6. Step 6: Final answer
   x = 883.18