Finding the Fourth Proportional to 2,859.59, 4,289.78 and 779.67

Step by Step Solution

1. Step 1: Write the proportion equation
   2,859.59 : 4,289.78 = 779.67 : x
2. Step 2: Convert to fraction form
   2,859.59/4,289.78 = 779.67/x
3. Step 3: Cross multiply
   2,859.59x = 4,289.78 × 779.67
4. Step 4: Simplify right side
   2,859.59x = 3,344,614.72
5. Step 5: Solve for x
   x = 3,344,614.72/2,859.59
6. Step 6: Final answer
   x = 1,169.61