Finding the Fourth Proportional to 2,659.30, 3,987.78 and 809.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,659.30 : 3,987.78 = 809.98 : x
2. Step 2: Convert to fraction form
   2,659.30/3,987.78 = 809.98/x
3. Step 3: Cross multiply
   2,659.30x = 3,987.78 × 809.98
4. Step 4: Simplify right side
   2,659.30x = 3,230,022.04
5. Step 5: Solve for x
   x = 3,230,022.04/2,659.30
6. Step 6: Final answer
   x = 1,214.62