Finding the Fourth Proportional to 1,397.07, 1,928.12 and 799.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.07 : 1,928.12 = 799.78 : x
2. Step 2: Convert to fraction form
   1,397.07/1,928.12 = 799.78/x
3. Step 3: Cross multiply
   1,397.07x = 1,928.12 × 799.78
4. Step 4: Simplify right side
   1,397.07x = 1,542,071.81
5. Step 5: Solve for x
   x = 1,542,071.81/1,397.07
6. Step 6: Final answer
   x = 1,103.79