Finding the Fourth Proportional to 2,606.85, 3,915.72 and 2,216.79

Step by Step Solution

1. Step 1: Write the proportion equation
   2,606.85 : 3,915.72 = 2,216.79 : x
2. Step 2: Convert to fraction form
   2,606.85/3,915.72 = 2,216.79/x
3. Step 3: Cross multiply
   2,606.85x = 3,915.72 × 2,216.79
4. Step 4: Simplify right side
   2,606.85x = 8,680,328.94
5. Step 5: Solve for x
   x = 8,680,328.94/2,606.85
6. Step 6: Final answer
   x = 3,329.82