Finding the Fourth Proportional to 2,876.22, 3,959.40 and 2,128.77

Step by Step Solution

1. Step 1: Write the proportion equation
   2,876.22 : 3,959.40 = 2,128.77 : x
2. Step 2: Convert to fraction form
   2,876.22/3,959.40 = 2,128.77/x
3. Step 3: Cross multiply
   2,876.22x = 3,959.40 × 2,128.77
4. Step 4: Simplify right side
   2,876.22x = 8,428,641.29
5. Step 5: Solve for x
   x = 8,428,641.29/2,876.22
6. Step 6: Final answer
   x = 2,930.46