Finding the Fourth Proportional to 1,439.66, 1,986.78 and 810.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.66 : 1,986.78 = 810.17 : x
2. Step 2: Convert to fraction form
   1,439.66/1,986.78 = 810.17/x
3. Step 3: Cross multiply
   1,439.66x = 1,986.78 × 810.17
4. Step 4: Simplify right side
   1,439.66x = 1,609,636.73
5. Step 5: Solve for x
   x = 1,609,636.73/1,439.66
6. Step 6: Final answer
   x = 1,118.07