Finding the Fourth Proportional to 1,399.17, 1,930.89 and 801.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.17 : 1,930.89 = 801.78 : x
2. Step 2: Convert to fraction form
   1,399.17/1,930.89 = 801.78/x
3. Step 3: Cross multiply
   1,399.17x = 1,930.89 × 801.78
4. Step 4: Simplify right side
   1,399.17x = 1,548,148.98
5. Step 5: Solve for x
   x = 1,548,148.98/1,399.17
6. Step 6: Final answer
   x = 1,106.48