Finding the Fourth Proportional to 2,661.22, 3,992.06 and 812.53

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.22 : 3,992.06 = 812.53 : x
2. Step 2: Convert to fraction form
   2,661.22/3,992.06 = 812.53/x
3. Step 3: Cross multiply
   2,661.22x = 3,992.06 × 812.53
4. Step 4: Simplify right side
   2,661.22x = 3,243,648.55
5. Step 5: Solve for x
   x = 3,243,648.55/2,661.22
6. Step 6: Final answer
   x = 1,218.86