Finding the Fourth Proportional to 5,591.50, 8,387.85 and 2,128.76

Step by Step Solution

1. Step 1: Write the proportion equation
   5,591.50 : 8,387.85 = 2,128.76 : x
2. Step 2: Convert to fraction form
   5,591.50/8,387.85 = 2,128.76/x
3. Step 3: Cross multiply
   5,591.50x = 8,387.85 × 2,128.76
4. Step 4: Simplify right side
   5,591.50x = 17,855,719.57
5. Step 5: Solve for x
   x = 17,855,719.57/5,591.50
6. Step 6: Final answer
   x = 3,193.37