Finding the Fourth Proportional to 2,621.82, 3,931.88 and 866.43

Step by Step Solution

1. Step 1: Write the proportion equation
   2,621.82 : 3,931.88 = 866.43 : x
2. Step 2: Convert to fraction form
   2,621.82/3,931.88 = 866.43/x
3. Step 3: Cross multiply
   2,621.82x = 3,931.88 × 866.43
4. Step 4: Simplify right side
   2,621.82x = 3,406,698.79
5. Step 5: Solve for x
   x = 3,406,698.79/2,621.82
6. Step 6: Final answer
   x = 1,299.36