Finding the Fourth Proportional to 2,648.28, 3,971.85 and 1,087.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,648.28 : 3,971.85 = 1,087.89 : x
2. Step 2: Convert to fraction form
   2,648.28/3,971.85 = 1,087.89/x
3. Step 3: Cross multiply
   2,648.28x = 3,971.85 × 1,087.89
4. Step 4: Simplify right side
   2,648.28x = 4,320,935.90
5. Step 5: Solve for x
   x = 4,320,935.90/2,648.28
6. Step 6: Final answer
   x = 1,631.60