Finding the Fourth Proportional to 2,543.72, 3,816.12 and 812.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,543.72 : 3,816.12 = 812.28 : x
2. Step 2: Convert to fraction form
   2,543.72/3,816.12 = 812.28/x
3. Step 3: Cross multiply
   2,543.72x = 3,816.12 × 812.28
4. Step 4: Simplify right side
   2,543.72x = 3,099,757.95
5. Step 5: Solve for x
   x = 3,099,757.95/2,543.72
6. Step 6: Final answer
   x = 1,218.59