Finding the Fourth Proportional to 1,391.58, 1,920.78 and 832.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.58 : 1,920.78 = 832.23 : x
2. Step 2: Convert to fraction form
   1,391.58/1,920.78 = 832.23/x
3. Step 3: Cross multiply
   1,391.58x = 1,920.78 × 832.23
4. Step 4: Simplify right side
   1,391.58x = 1,598,530.74
5. Step 5: Solve for x
   x = 1,598,530.74/1,391.58
6. Step 6: Final answer
   x = 1,148.72