Finding the Fourth Proportional to 3,778.89, 5,214.78 and 2,100.21

Step by Step Solution

1. Step 1: Write the proportion equation
   3,778.89 : 5,214.78 = 2,100.21 : x
2. Step 2: Convert to fraction form
   3,778.89/5,214.78 = 2,100.21/x
3. Step 3: Cross multiply
   3,778.89x = 5,214.78 × 2,100.21
4. Step 4: Simplify right side
   3,778.89x = 10,952,133.10
5. Step 5: Solve for x
   x = 10,952,133.10/3,778.89
6. Step 6: Final answer
   x = 2,898.24