Finding the Fourth Proportional to 2,016.40, 3,022.96 and 921.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,016.40 : 3,022.96 = 921.28 : x
2. Step 2: Convert to fraction form
   2,016.40/3,022.96 = 921.28/x
3. Step 3: Cross multiply
   2,016.40x = 3,022.96 × 921.28
4. Step 4: Simplify right side
   2,016.40x = 2,784,992.59
5. Step 5: Solve for x
   x = 2,784,992.59/2,016.40
6. Step 6: Final answer
   x = 1,381.17