Finding the Fourth Proportional to 1,439.60, 1,986.44 and 818.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.60 : 1,986.44 = 818.56 : x
2. Step 2: Convert to fraction form
   1,439.60/1,986.44 = 818.56/x
3. Step 3: Cross multiply
   1,439.60x = 1,986.44 × 818.56
4. Step 4: Simplify right side
   1,439.60x = 1,626,020.33
5. Step 5: Solve for x
   x = 1,626,020.33/1,439.60
6. Step 6: Final answer
   x = 1,129.49