Finding the Fourth Proportional to 1,082.79, 1,494.06 and 640.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,082.79 : 1,494.06 = 640.53 : x
2. Step 2: Convert to fraction form
   1,082.79/1,494.06 = 640.53/x
3. Step 3: Cross multiply
   1,082.79x = 1,494.06 × 640.53
4. Step 4: Simplify right side
   1,082.79x = 956,987.85
5. Step 5: Solve for x
   x = 956,987.85/1,082.79
6. Step 6: Final answer
   x = 883.82