Finding the Fourth Proportional to 1,057.90, 1,458.50 and 868.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,057.90 : 1,458.50 = 868.15 : x
2. Step 2: Convert to fraction form
   1,057.90/1,458.50 = 868.15/x
3. Step 3: Cross multiply
   1,057.90x = 1,458.50 × 868.15
4. Step 4: Simplify right side
   1,057.90x = 1,266,187.31
5. Step 5: Solve for x
   x = 1,266,187.31/1,057.90
6. Step 6: Final answer
   x = 1,196.89