Finding the Fourth Proportional to 2,087.13, 3,131.91 and 788.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,087.13 : 3,131.91 = 788.70 : x
2. Step 2: Convert to fraction form
   2,087.13/3,131.91 = 788.70/x
3. Step 3: Cross multiply
   2,087.13x = 3,131.91 × 788.70
4. Step 4: Simplify right side
   2,087.13x = 2,470,137.42
5. Step 5: Solve for x
   x = 2,470,137.42/2,087.13
6. Step 6: Final answer
   x = 1,183.51