Finding the Fourth Proportional to 1,399.32, 1,931.49 and 810.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.32 : 1,931.49 = 810.09 : x
2. Step 2: Convert to fraction form
   1,399.32/1,931.49 = 810.09/x
3. Step 3: Cross multiply
   1,399.32x = 1,931.49 × 810.09
4. Step 4: Simplify right side
   1,399.32x = 1,564,680.73
5. Step 5: Solve for x
   x = 1,564,680.73/1,399.32
6. Step 6: Final answer
   x = 1,118.17