Finding the Fourth Proportional to 1,439.72, 1,986.77 and 810.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.72 : 1,986.77 = 810.26 : x
2. Step 2: Convert to fraction form
   1,439.72/1,986.77 = 810.26/x
3. Step 3: Cross multiply
   1,439.72x = 1,986.77 × 810.26
4. Step 4: Simplify right side
   1,439.72x = 1,609,796.21
5. Step 5: Solve for x
   x = 1,609,796.21/1,439.72
6. Step 6: Final answer
   x = 1,118.13