Finding the Fourth Proportional to 2,100.88, 3,151.33 and 640.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.88 : 3,151.33 = 640.02 : x
2. Step 2: Convert to fraction form
   2,100.88/3,151.33 = 640.02/x
3. Step 3: Cross multiply
   2,100.88x = 3,151.33 × 640.02
4. Step 4: Simplify right side
   2,100.88x = 2,016,914.23
5. Step 5: Solve for x
   x = 2,016,914.23/2,100.88
6. Step 6: Final answer
   x = 960.03