Finding the Fourth Proportional to 1,439.42, 1,986.36 and 810.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.42 : 1,986.36 = 810.02 : x
2. Step 2: Convert to fraction form
   1,439.42/1,986.36 = 810.02/x
3. Step 3: Cross multiply
   1,439.42x = 1,986.36 × 810.02
4. Step 4: Simplify right side
   1,439.42x = 1,608,991.33
5. Step 5: Solve for x
   x = 1,608,991.33/1,439.42
6. Step 6: Final answer
   x = 1,117.81