Finding the Fourth Proportional to 2,142.21, 3,211.22 and 680.33

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.21 : 3,211.22 = 680.33 : x
2. Step 2: Convert to fraction form
   2,142.21/3,211.22 = 680.33/x
3. Step 3: Cross multiply
   2,142.21x = 3,211.22 × 680.33
4. Step 4: Simplify right side
   2,142.21x = 2,184,669.84
5. Step 5: Solve for x
   x = 2,184,669.84/2,142.21
6. Step 6: Final answer
   x = 1,019.82