Finding the Fourth Proportional to 2,665.80, 3,999.04 and 1,431.52

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.80 : 3,999.04 = 1,431.52 : x
2. Step 2: Convert to fraction form
   2,665.80/3,999.04 = 1,431.52/x
3. Step 3: Cross multiply
   2,665.80x = 3,999.04 × 1,431.52
4. Step 4: Simplify right side
   2,665.80x = 5,724,705.74
5. Step 5: Solve for x
   x = 5,724,705.74/2,665.80
6. Step 6: Final answer
   x = 2,147.46