Finding the Fourth Proportional to 3,900.30, 5,381.94 and 2,221.71

Step by Step Solution

1. Step 1: Write the proportion equation
   3,900.30 : 5,381.94 = 2,221.71 : x
2. Step 2: Convert to fraction form
   3,900.30/5,381.94 = 2,221.71/x
3. Step 3: Cross multiply
   3,900.30x = 5,381.94 × 2,221.71
4. Step 4: Simplify right side
   3,900.30x = 11,957,109.92
5. Step 5: Solve for x
   x = 11,957,109.92/3,900.30
6. Step 6: Final answer
   x = 3,065.69