Finding the Fourth Proportional to 1,399.88, 1,931.83 and 810.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.88 : 1,931.83 = 810.46 : x
2. Step 2: Convert to fraction form
   1,399.88/1,931.83 = 810.46/x
3. Step 3: Cross multiply
   1,399.88x = 1,931.83 × 810.46
4. Step 4: Simplify right side
   1,399.88x = 1,565,670.94
5. Step 5: Solve for x
   x = 1,565,670.94/1,399.88
6. Step 6: Final answer
   x = 1,118.43