Finding the Fourth Proportional to 2,143.36, 3,216.86 and 845.74

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.36 : 3,216.86 = 845.74 : x
2. Step 2: Convert to fraction form
   2,143.36/3,216.86 = 845.74/x
3. Step 3: Cross multiply
   2,143.36x = 3,216.86 × 845.74
4. Step 4: Simplify right side
   2,143.36x = 2,720,606.86
5. Step 5: Solve for x
   x = 2,720,606.86/2,143.36
6. Step 6: Final answer
   x = 1,269.32