Finding the Fourth Proportional to 5,591.60, 8,385.78 and 2,128.04

Step by Step Solution

1. Step 1: Write the proportion equation
   5,591.60 : 8,385.78 = 2,128.04 : x
2. Step 2: Convert to fraction form
   5,591.60/8,385.78 = 2,128.04/x
3. Step 3: Cross multiply
   5,591.60x = 8,385.78 × 2,128.04
4. Step 4: Simplify right side
   5,591.60x = 17,845,275.27
5. Step 5: Solve for x
   x = 17,845,275.27/5,591.60
6. Step 6: Final answer
   x = 3,191.44