Finding the Fourth Proportional to 1,091.00, 1,505.79 and 857.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.00 : 1,505.79 = 857.72 : x
2. Step 2: Convert to fraction form
   1,091.00/1,505.79 = 857.72/x
3. Step 3: Cross multiply
   1,091.00x = 1,505.79 × 857.72
4. Step 4: Simplify right side
   1,091.00x = 1,291,538.67
5. Step 5: Solve for x
   x = 1,291,538.67/1,091.00
6. Step 6: Final answer
   x = 1,183.82