Finding the Fourth Proportional to 776.15, 1,155.43 and 772.05

Step by Step Solution

1. Step 1: Write the proportion equation
   776.15 : 1,155.43 = 772.05 : x
2. Step 2: Convert to fraction form
   776.15/1,155.43 = 772.05/x
3. Step 3: Cross multiply
   776.15x = 1,155.43 × 772.05
4. Step 4: Simplify right side
   776.15x = 892,050.69
5. Step 5: Solve for x
   x = 892,050.69/776.15
6. Step 6: Final answer
   x = 1,149.33