Finding the Fourth Proportional to 2,620.91, 3,928.82 and 864.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.91 : 3,928.82 = 864.70 : x
2. Step 2: Convert to fraction form
   2,620.91/3,928.82 = 864.70/x
3. Step 3: Cross multiply
   2,620.91x = 3,928.82 × 864.70
4. Step 4: Simplify right side
   2,620.91x = 3,397,250.65
5. Step 5: Solve for x
   x = 3,397,250.65/2,620.91
6. Step 6: Final answer
   x = 1,296.21