Finding the Fourth Proportional to 1,311.31, 1,808.28 and 957.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.31 : 1,808.28 = 957.29 : x
2. Step 2: Convert to fraction form
   1,311.31/1,808.28 = 957.29/x
3. Step 3: Cross multiply
   1,311.31x = 1,808.28 × 957.29
4. Step 4: Simplify right side
   1,311.31x = 1,731,049.69
5. Step 5: Solve for x
   x = 1,731,049.69/1,311.31
6. Step 6: Final answer
   x = 1,320.09