Finding the Fourth Proportional to 2,653.97, 3,978.52 and 921.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,653.97 : 3,978.52 = 921.38 : x
2. Step 2: Convert to fraction form
   2,653.97/3,978.52 = 921.38/x
3. Step 3: Cross multiply
   2,653.97x = 3,978.52 × 921.38
4. Step 4: Simplify right side
   2,653.97x = 3,665,706.56
5. Step 5: Solve for x
   x = 3,665,706.56/2,653.97
6. Step 6: Final answer
   x = 1,381.22