Finding the Fourth Proportional to 2,087.22, 3,130.90 and 788.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,087.22 : 3,130.90 = 788.78 : x
2. Step 2: Convert to fraction form
   2,087.22/3,130.90 = 788.78/x
3. Step 3: Cross multiply
   2,087.22x = 3,130.90 × 788.78
4. Step 4: Simplify right side
   2,087.22x = 2,469,591.30
5. Step 5: Solve for x
   x = 2,469,591.30/2,087.22
6. Step 6: Final answer
   x = 1,183.20