Finding the Fourth Proportional to 2,611.78, 3,918.24 and 763.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,611.78 : 3,918.24 = 763.05 : x
2. Step 2: Convert to fraction form
   2,611.78/3,918.24 = 763.05/x
3. Step 3: Cross multiply
   2,611.78x = 3,918.24 × 763.05
4. Step 4: Simplify right side
   2,611.78x = 2,989,813.03
5. Step 5: Solve for x
   x = 2,989,813.03/2,611.78
6. Step 6: Final answer
   x = 1,144.74