Finding the Fourth Proportional to 1,391.12, 2,085.86 and 957.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.12 : 2,085.86 = 957.77 : x
2. Step 2: Convert to fraction form
   1,391.12/2,085.86 = 957.77/x
3. Step 3: Cross multiply
   1,391.12x = 2,085.86 × 957.77
4. Step 4: Simplify right side
   1,391.12x = 1,997,766.10
5. Step 5: Solve for x
   x = 1,997,766.10/1,391.12
6. Step 6: Final answer
   x = 1,436.09