Finding the Fourth Proportional to 2,760.12, 4,138.76 and 812.07

Step by Step Solution

1. Step 1: Write the proportion equation
   2,760.12 : 4,138.76 = 812.07 : x
2. Step 2: Convert to fraction form
   2,760.12/4,138.76 = 812.07/x
3. Step 3: Cross multiply
   2,760.12x = 4,138.76 × 812.07
4. Step 4: Simplify right side
   2,760.12x = 3,360,962.83
5. Step 5: Solve for x
   x = 3,360,962.83/2,760.12
6. Step 6: Final answer
   x = 1,217.69