Finding the Fourth Proportional to 2,659.42, 3,988.94 and 810.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,659.42 : 3,988.94 = 810.60 : x
2. Step 2: Convert to fraction form
   2,659.42/3,988.94 = 810.60/x
3. Step 3: Cross multiply
   2,659.42x = 3,988.94 × 810.60
4. Step 4: Simplify right side
   2,659.42x = 3,233,434.76
5. Step 5: Solve for x
   x = 3,233,434.76/2,659.42
6. Step 6: Final answer
   x = 1,215.84