Finding the Fourth Proportional to 2,259.91, 3,389.04 and 778.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,259.91 : 3,389.04 = 778.72 : x
2. Step 2: Convert to fraction form
   2,259.91/3,389.04 = 778.72/x
3. Step 3: Cross multiply
   2,259.91x = 3,389.04 × 778.72
4. Step 4: Simplify right side
   2,259.91x = 2,639,113.23
5. Step 5: Solve for x
   x = 2,639,113.23/2,259.91
6. Step 6: Final answer
   x = 1,167.80