Finding the Fourth Proportional to 1,399.93, 1,931.69 and 810.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.93 : 1,931.69 = 810.36 : x
2. Step 2: Convert to fraction form
   1,399.93/1,931.69 = 810.36/x
3. Step 3: Cross multiply
   1,399.93x = 1,931.69 × 810.36
4. Step 4: Simplify right side
   1,399.93x = 1,565,366.33
5. Step 5: Solve for x
   x = 1,565,366.33/1,399.93
6. Step 6: Final answer
   x = 1,118.18