Finding the Fourth Proportional to 3,861.09, 5,786.55 and 2,106.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,861.09 : 5,786.55 = 2,106.86 : x
2. Step 2: Convert to fraction form
   3,861.09/5,786.55 = 2,106.86/x
3. Step 3: Cross multiply
   3,861.09x = 5,786.55 × 2,106.86
4. Step 4: Simplify right side
   3,861.09x = 12,191,421.80
5. Step 5: Solve for x
   x = 12,191,421.80/3,861.09
6. Step 6: Final answer
   x = 3,157.51