Finding the Fourth Proportional to 1,813.55, 2,717.78 and 772.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,813.55 : 2,717.78 = 772.15 : x
2. Step 2: Convert to fraction form
   1,813.55/2,717.78 = 772.15/x
3. Step 3: Cross multiply
   1,813.55x = 2,717.78 × 772.15
4. Step 4: Simplify right side
   1,813.55x = 2,098,533.83
5. Step 5: Solve for x
   x = 2,098,533.83/1,813.55
6. Step 6: Final answer
   x = 1,157.14