Finding the Fourth Proportional to 2,164.81, 3,245.39 and 865.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,164.81 : 3,245.39 = 865.57 : x
2. Step 2: Convert to fraction form
   2,164.81/3,245.39 = 865.57/x
3. Step 3: Cross multiply
   2,164.81x = 3,245.39 × 865.57
4. Step 4: Simplify right side
   2,164.81x = 2,809,114.39
5. Step 5: Solve for x
   x = 2,809,114.39/2,164.81
6. Step 6: Final answer
   x = 1,297.63