Finding the Fourth Proportional to 1,399.92, 1,931.82 and 810.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.92 : 1,931.82 = 810.42 : x
2. Step 2: Convert to fraction form
   1,399.92/1,931.82 = 810.42/x
3. Step 3: Cross multiply
   1,399.92x = 1,931.82 × 810.42
4. Step 4: Simplify right side
   1,399.92x = 1,565,585.56
5. Step 5: Solve for x
   x = 1,565,585.56/1,399.92
6. Step 6: Final answer
   x = 1,118.34