Finding the Fourth Proportional to 2,101.68, 3,152.52 and 640.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,101.68 : 3,152.52 = 640.82 : x
2. Step 2: Convert to fraction form
   2,101.68/3,152.52 = 640.82/x
3. Step 3: Cross multiply
   2,101.68x = 3,152.52 × 640.82
4. Step 4: Simplify right side
   2,101.68x = 2,020,208.15
5. Step 5: Solve for x
   x = 2,020,208.15/2,101.68
6. Step 6: Final answer
   x = 961.23