Finding the Fourth Proportional to 2,109.31, 3,164.51 and 810.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.31 : 3,164.51 = 810.88 : x
2. Step 2: Convert to fraction form
   2,109.31/3,164.51 = 810.88/x
3. Step 3: Cross multiply
   2,109.31x = 3,164.51 × 810.88
4. Step 4: Simplify right side
   2,109.31x = 2,566,037.87
5. Step 5: Solve for x
   x = 2,566,037.87/2,109.31
6. Step 6: Final answer
   x = 1,216.53