Finding the Fourth Proportional to 2,109.37, 3,165.32 and 811.93

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.37 : 3,165.32 = 811.93 : x
2. Step 2: Convert to fraction form
   2,109.37/3,165.32 = 811.93/x
3. Step 3: Cross multiply
   2,109.37x = 3,165.32 × 811.93
4. Step 4: Simplify right side
   2,109.37x = 2,570,018.27
5. Step 5: Solve for x
   x = 2,570,018.27/2,109.37
6. Step 6: Final answer
   x = 1,218.38