Finding the Fourth Proportional to 1,392.58, 1,921.48 and 803.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.58 : 1,921.48 = 803.31 : x
2. Step 2: Convert to fraction form
   1,392.58/1,921.48 = 803.31/x
3. Step 3: Cross multiply
   1,392.58x = 1,921.48 × 803.31
4. Step 4: Simplify right side
   1,392.58x = 1,543,544.10
5. Step 5: Solve for x
   x = 1,543,544.10/1,392.58
6. Step 6: Final answer
   x = 1,108.41