Finding the Fourth Proportional to 2,611.88, 3,917.51 and 664.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,611.88 : 3,917.51 = 664.10 : x
2. Step 2: Convert to fraction form
   2,611.88/3,917.51 = 664.10/x
3. Step 3: Cross multiply
   2,611.88x = 3,917.51 × 664.10
4. Step 4: Simplify right side
   2,611.88x = 2,601,595.48
5. Step 5: Solve for x
   x = 2,601,595.48/2,611.88
6. Step 6: Final answer
   x = 996.06