Finding the Fourth Proportional to 1,439.73, 1,986.36 and 810.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.73 : 1,986.36 = 810.15 : x
2. Step 2: Convert to fraction form
   1,439.73/1,986.36 = 810.15/x
3. Step 3: Cross multiply
   1,439.73x = 1,986.36 × 810.15
4. Step 4: Simplify right side
   1,439.73x = 1,609,249.55
5. Step 5: Solve for x
   x = 1,609,249.55/1,439.73
6. Step 6: Final answer
   x = 1,117.74