Finding the Fourth Proportional to 1,318.96, 1,977.72 and 772.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,318.96 : 1,977.72 = 772.18 : x
2. Step 2: Convert to fraction form
   1,318.96/1,977.72 = 772.18/x
3. Step 3: Cross multiply
   1,318.96x = 1,977.72 × 772.18
4. Step 4: Simplify right side
   1,318.96x = 1,527,155.83
5. Step 5: Solve for x
   x = 1,527,155.83/1,318.96
6. Step 6: Final answer
   x = 1,157.85