Finding the Fourth Proportional to 2,621.78, 3,932.85 and 866.71

Step by Step Solution

1. Step 1: Write the proportion equation
   2,621.78 : 3,932.85 = 866.71 : x
2. Step 2: Convert to fraction form
   2,621.78/3,932.85 = 866.71/x
3. Step 3: Cross multiply
   2,621.78x = 3,932.85 × 866.71
4. Step 4: Simplify right side
   2,621.78x = 3,408,648.59
5. Step 5: Solve for x
   x = 3,408,648.59/2,621.78
6. Step 6: Final answer
   x = 1,300.13