Finding the Fourth Proportional to 2,290.55, 3,436.20 and 831.74

Step by Step Solution

1. Step 1: Write the proportion equation
   2,290.55 : 3,436.20 = 831.74 : x
2. Step 2: Convert to fraction form
   2,290.55/3,436.20 = 831.74/x
3. Step 3: Cross multiply
   2,290.55x = 3,436.20 × 831.74
4. Step 4: Simplify right side
   2,290.55x = 2,858,007.81
5. Step 5: Solve for x
   x = 2,858,007.81/2,290.55
6. Step 6: Final answer
   x = 1,247.74