Finding the Fourth Proportional to 2,807.31, 4,209.54 and 957.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,807.31 : 4,209.54 = 957.78 : x
2. Step 2: Convert to fraction form
   2,807.31/4,209.54 = 957.78/x
3. Step 3: Cross multiply
   2,807.31x = 4,209.54 × 957.78
4. Step 4: Simplify right side
   2,807.31x = 4,031,813.22
5. Step 5: Solve for x
   x = 4,031,813.22/2,807.31
6. Step 6: Final answer
   x = 1,436.18