Finding the Fourth Proportional to 5,091.71, 7,636.33 and 2,128.55

Step by Step Solution

1. Step 1: Write the proportion equation
   5,091.71 : 7,636.33 = 2,128.55 : x
2. Step 2: Convert to fraction form
   5,091.71/7,636.33 = 2,128.55/x
3. Step 3: Cross multiply
   5,091.71x = 7,636.33 × 2,128.55
4. Step 4: Simplify right side
   5,091.71x = 16,254,310.22
5. Step 5: Solve for x
   x = 16,254,310.22/5,091.71
6. Step 6: Final answer
   x = 3,192.31