Finding the Fourth Proportional to 1,662.12, 2,292.71 and 1,439.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,662.12 : 2,292.71 = 1,439.78 : x
2. Step 2: Convert to fraction form
   1,662.12/2,292.71 = 1,439.78/x
3. Step 3: Cross multiply
   1,662.12x = 2,292.71 × 1,439.78
4. Step 4: Simplify right side
   1,662.12x = 3,300,979.34
5. Step 5: Solve for x
   x = 3,300,979.34/1,662.12
6. Step 6: Final answer
   x = 1,986.01