Finding the Fourth Proportional to 3,856.55, 5,786.55 and 3,690.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,856.55 : 5,786.55 = 3,690.50 : x
2. Step 2: Convert to fraction form
   3,856.55/5,786.55 = 3,690.50/x
3. Step 3: Cross multiply
   3,856.55x = 5,786.55 × 3,690.50
4. Step 4: Simplify right side
   3,856.55x = 21,355,233.84
5. Step 5: Solve for x
   x = 21,355,233.84/3,856.55
6. Step 6: Final answer
   x = 5,537.40