Finding the Fourth Proportional to 2,620.40, 3,900.07 and 2,612.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.40 : 3,900.07 = 2,612.30 : x
2. Step 2: Convert to fraction form
   2,620.40/3,900.07 = 2,612.30/x
3. Step 3: Cross multiply
   2,620.40x = 3,900.07 × 2,612.30
4. Step 4: Simplify right side
   2,620.40x = 10,188,152.86
5. Step 5: Solve for x
   x = 10,188,152.86/2,620.40
6. Step 6: Final answer
   x = 3,888.01