Finding the Fourth Proportional to 1,392.51, 1,921.67 and 803.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.51 : 1,921.67 = 803.05 : x
2. Step 2: Convert to fraction form
   1,392.51/1,921.67 = 803.05/x
3. Step 3: Cross multiply
   1,392.51x = 1,921.67 × 803.05
4. Step 4: Simplify right side
   1,392.51x = 1,543,197.09
5. Step 5: Solve for x
   x = 1,543,197.09/1,392.51
6. Step 6: Final answer
   x = 1,108.21