Finding the Fourth Proportional to 2,621.39, 3,931.13 and 866.07

Step by Step Solution

1. Step 1: Write the proportion equation
   2,621.39 : 3,931.13 = 866.07 : x
2. Step 2: Convert to fraction form
   2,621.39/3,931.13 = 866.07/x
3. Step 3: Cross multiply
   2,621.39x = 3,931.13 × 866.07
4. Step 4: Simplify right side
   2,621.39x = 3,404,635.92
5. Step 5: Solve for x
   x = 3,404,635.92/2,621.39
6. Step 6: Final answer
   x = 1,298.79