Finding the Fourth Proportional to 1,399.46, 1,931.38 and 810.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.46 : 1,931.38 = 810.18 : x
2. Step 2: Convert to fraction form
   1,399.46/1,931.38 = 810.18/x
3. Step 3: Cross multiply
   1,399.46x = 1,931.38 × 810.18
4. Step 4: Simplify right side
   1,399.46x = 1,564,763.42
5. Step 5: Solve for x
   x = 1,564,763.42/1,399.46
6. Step 6: Final answer
   x = 1,118.12