Finding the Fourth Proportional to 2,611.55, 3,917.31 and 637.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,611.55 : 3,917.31 = 637.15 : x
2. Step 2: Convert to fraction form
   2,611.55/3,917.31 = 637.15/x
3. Step 3: Cross multiply
   2,611.55x = 3,917.31 × 637.15
4. Step 4: Simplify right side
   2,611.55x = 2,495,910.88
5. Step 5: Solve for x
   x = 2,495,910.88/2,611.55
6. Step 6: Final answer
   x = 955.72