Finding the Fourth Proportional to 2,100.93, 3,151.83 and 640.04

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.93 : 3,151.83 = 640.04 : x
2. Step 2: Convert to fraction form
   2,100.93/3,151.83 = 640.04/x
3. Step 3: Cross multiply
   2,100.93x = 3,151.83 × 640.04
4. Step 4: Simplify right side
   2,100.93x = 2,017,297.27
5. Step 5: Solve for x
   x = 2,017,297.27/2,100.93
6. Step 6: Final answer
   x = 960.19