Finding the Fourth Proportional to 1,389.27, 1,917.10 and 791.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.27 : 1,917.10 = 791.69 : x
2. Step 2: Convert to fraction form
   1,389.27/1,917.10 = 791.69/x
3. Step 3: Cross multiply
   1,389.27x = 1,917.10 × 791.69
4. Step 4: Simplify right side
   1,389.27x = 1,517,744.11
5. Step 5: Solve for x
   x = 1,517,744.11/1,389.27
6. Step 6: Final answer
   x = 1,092.48