Finding the Fourth Proportional to 1,392.65, 1,921.72 and 803.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.65 : 1,921.72 = 803.10 : x
2. Step 2: Convert to fraction form
   1,392.65/1,921.72 = 803.10/x
3. Step 3: Cross multiply
   1,392.65x = 1,921.72 × 803.10
4. Step 4: Simplify right side
   1,392.65x = 1,543,333.33
5. Step 5: Solve for x
   x = 1,543,333.33/1,392.65
6. Step 6: Final answer
   x = 1,108.20