Finding the Fourth Proportional to 2,121.21, 3,180.78 and 734.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,121.21 : 3,180.78 = 734.05 : x
2. Step 2: Convert to fraction form
   2,121.21/3,180.78 = 734.05/x
3. Step 3: Cross multiply
   2,121.21x = 3,180.78 × 734.05
4. Step 4: Simplify right side
   2,121.21x = 2,334,851.56
5. Step 5: Solve for x
   x = 2,334,851.56/2,121.21
6. Step 6: Final answer
   x = 1,100.72