Finding the Fourth Proportional to 2,659.94, 3,988.57 and 810.62

Step by Step Solution

1. Step 1: Write the proportion equation
   2,659.94 : 3,988.57 = 810.62 : x
2. Step 2: Convert to fraction form
   2,659.94/3,988.57 = 810.62/x
3. Step 3: Cross multiply
   2,659.94x = 3,988.57 × 810.62
4. Step 4: Simplify right side
   2,659.94x = 3,233,214.61
5. Step 5: Solve for x
   x = 3,233,214.61/2,659.94
6. Step 6: Final answer
   x = 1,215.52