Finding the Fourth Proportional to 2,611.40, 3,907.85 and 1,916.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,611.40 : 3,907.85 = 1,916.42 : x
2. Step 2: Convert to fraction form
   2,611.40/3,907.85 = 1,916.42/x
3. Step 3: Cross multiply
   2,611.40x = 3,907.85 × 1,916.42
4. Step 4: Simplify right side
   2,611.40x = 7,489,052.78
5. Step 5: Solve for x
   x = 7,489,052.78/2,611.40
6. Step 6: Final answer
   x = 2,867.84