Finding the Fourth Proportional to 2,279.25, 3,145.37 and 1,231.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,279.25 : 3,145.37 = 1,231.31 : x
2. Step 2: Convert to fraction form
   2,279.25/3,145.37 = 1,231.31/x
3. Step 3: Cross multiply
   2,279.25x = 3,145.37 × 1,231.31
4. Step 4: Simplify right side
   2,279.25x = 3,872,936.48
5. Step 5: Solve for x
   x = 3,872,936.48/2,279.25
6. Step 6: Final answer
   x = 1,699.22