Finding the Fourth Proportional to 1,439.48, 1,986.59 and 810.11

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.48 : 1,986.59 = 810.11 : x
2. Step 2: Convert to fraction form
   1,439.48/1,986.59 = 810.11/x
3. Step 3: Cross multiply
   1,439.48x = 1,986.59 × 810.11
4. Step 4: Simplify right side
   1,439.48x = 1,609,363.42
5. Step 5: Solve for x
   x = 1,609,363.42/1,439.48
6. Step 6: Final answer
   x = 1,118.02