Finding the Fourth Proportional to 2,128.24, 3,188.88 and 1,086.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.24 : 3,188.88 = 1,086.80 : x
2. Step 2: Convert to fraction form
   2,128.24/3,188.88 = 1,086.80/x
3. Step 3: Cross multiply
   2,128.24x = 3,188.88 × 1,086.80
4. Step 4: Simplify right side
   2,128.24x = 3,465,674.78
5. Step 5: Solve for x
   x = 3,465,674.78/2,128.24
6. Step 6: Final answer
   x = 1,628.42