Finding the Fourth Proportional to 2,100.75, 3,151.58 and 640.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.75 : 3,151.58 = 640.02 : x
2. Step 2: Convert to fraction form
   2,100.75/3,151.58 = 640.02/x
3. Step 3: Cross multiply
   2,100.75x = 3,151.58 × 640.02
4. Step 4: Simplify right side
   2,100.75x = 2,017,074.23
5. Step 5: Solve for x
   x = 2,017,074.23/2,100.75
6. Step 6: Final answer
   x = 960.17