Finding the Fourth Proportional to 2,141.96, 3,212.88 and 681.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,141.96 : 3,212.88 = 681.20 : x
2. Step 2: Convert to fraction form
   2,141.96/3,212.88 = 681.20/x
3. Step 3: Cross multiply
   2,141.96x = 3,212.88 × 681.20
4. Step 4: Simplify right side
   2,141.96x = 2,188,613.86
5. Step 5: Solve for x
   x = 2,188,613.86/2,141.96
6. Step 6: Final answer
   x = 1,021.78