Finding the Fourth Proportional to 1,389.30, 1,917.29 and 799.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.30 : 1,917.29 = 799.83 : x
2. Step 2: Convert to fraction form
   1,389.30/1,917.29 = 799.83/x
3. Step 3: Cross multiply
   1,389.30x = 1,917.29 × 799.83
4. Step 4: Simplify right side
   1,389.30x = 1,533,506.06
5. Step 5: Solve for x
   x = 1,533,506.06/1,389.30
6. Step 6: Final answer
   x = 1,103.80