Finding the Fourth Proportional to 2,661.56, 3,990.82 and 812.14

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.56 : 3,990.82 = 812.14 : x
2. Step 2: Convert to fraction form
   2,661.56/3,990.82 = 812.14/x
3. Step 3: Cross multiply
   2,661.56x = 3,990.82 × 812.14
4. Step 4: Simplify right side
   2,661.56x = 3,241,104.55
5. Step 5: Solve for x
   x = 3,241,104.55/2,661.56
6. Step 6: Final answer
   x = 1,217.75