Finding the Fourth Proportional to 2,780.07, 4,168.89 and 831.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,780.07 : 4,168.89 = 831.82 : x
2. Step 2: Convert to fraction form
   2,780.07/4,168.89 = 831.82/x
3. Step 3: Cross multiply
   2,780.07x = 4,168.89 × 831.82
4. Step 4: Simplify right side
   2,780.07x = 3,467,765.81
5. Step 5: Solve for x
   x = 3,467,765.81/2,780.07
6. Step 6: Final answer
   x = 1,247.37