Finding the Fourth Proportional to 2,661.27, 3,991.89 and 812.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.27 : 3,991.89 = 812.38 : x
2. Step 2: Convert to fraction form
   2,661.27/3,991.89 = 812.38/x
3. Step 3: Cross multiply
   2,661.27x = 3,991.89 × 812.38
4. Step 4: Simplify right side
   2,661.27x = 3,242,929.86
5. Step 5: Solve for x
   x = 3,242,929.86/2,661.27
6. Step 6: Final answer
   x = 1,218.56