Finding the Fourth Proportional to 2,768.31, 4,151.88 and 820.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,768.31 : 4,151.88 = 820.05 : x
2. Step 2: Convert to fraction form
   2,768.31/4,151.88 = 820.05/x
3. Step 3: Cross multiply
   2,768.31x = 4,151.88 × 820.05
4. Step 4: Simplify right side
   2,768.31x = 3,404,749.19
5. Step 5: Solve for x
   x = 3,404,749.19/2,768.31
6. Step 6: Final answer
   x = 1,229.90