Finding the Fourth Proportional to 1,162.96, 1,604.75 and 639.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,162.96 : 1,604.75 = 639.02 : x
2. Step 2: Convert to fraction form
   1,162.96/1,604.75 = 639.02/x
3. Step 3: Cross multiply
   1,162.96x = 1,604.75 × 639.02
4. Step 4: Simplify right side
   1,162.96x = 1,025,468.16
5. Step 5: Solve for x
   x = 1,025,468.16/1,162.96
6. Step 6: Final answer
   x = 881.78