Finding the Fourth Proportional to 2,640.64, 3,961.50 and 885.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,640.64 : 3,961.50 = 885.82 : x
2. Step 2: Convert to fraction form
   2,640.64/3,961.50 = 885.82/x
3. Step 3: Cross multiply
   2,640.64x = 3,961.50 × 885.82
4. Step 4: Simplify right side
   2,640.64x = 3,509,175.93
5. Step 5: Solve for x
   x = 3,509,175.93/2,640.64
6. Step 6: Final answer
   x = 1,328.91