Finding the Fourth Proportional to 2,172.43, 2,999.36 and 1,288.52

Step by Step Solution

1. Step 1: Write the proportion equation
   2,172.43 : 2,999.36 = 1,288.52 : x
2. Step 2: Convert to fraction form
   2,172.43/2,999.36 = 1,288.52/x
3. Step 3: Cross multiply
   2,172.43x = 2,999.36 × 1,288.52
4. Step 4: Simplify right side
   2,172.43x = 3,864,713.91
5. Step 5: Solve for x
   x = 3,864,713.91/2,172.43
6. Step 6: Final answer
   x = 1,778.98