Finding the Fourth Proportional to 2,859.18, 4,288.72 and 779.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,859.18 : 4,288.72 = 779.15 : x
2. Step 2: Convert to fraction form
   2,859.18/4,288.72 = 779.15/x
3. Step 3: Cross multiply
   2,859.18x = 4,288.72 × 779.15
4. Step 4: Simplify right side
   2,859.18x = 3,341,564.96
5. Step 5: Solve for x
   x = 3,341,564.96/2,859.18
6. Step 6: Final answer
   x = 1,168.71