Finding the Fourth Proportional to 3,861.16, 5,786.34 and 2,815

Step by Step Solution

1. Step 1: Write the proportion equation
   3,861.16 : 5,786.34 = 2,815 : x
2. Step 2: Convert to fraction form
   3,861.16/5,786.34 = 2,815/x
3. Step 3: Cross multiply
   3,861.16x = 5,786.34 × 2,815
4. Step 4: Simplify right side
   3,861.16x = 16,288,547.10
5. Step 5: Solve for x
   x = 16,288,547.10/3,861.16
6. Step 6: Final answer
   x = 4,218.56