Finding the Fourth Proportional to 1,391.33, 1,919.57 and 824.19

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.33 : 1,919.57 = 824.19 : x
2. Step 2: Convert to fraction form
   1,391.33/1,919.57 = 824.19/x
3. Step 3: Cross multiply
   1,391.33x = 1,919.57 × 824.19
4. Step 4: Simplify right side
   1,391.33x = 1,582,086.28
5. Step 5: Solve for x
   x = 1,582,086.28/1,391.33
6. Step 6: Final answer
   x = 1,137.11