Finding the Fourth Proportional to 3,781.89, 5,218.79 and 2,103.21

Step by Step Solution

1. Step 1: Write the proportion equation
   3,781.89 : 5,218.79 = 2,103.21 : x
2. Step 2: Convert to fraction form
   3,781.89/5,218.79 = 2,103.21/x
3. Step 3: Cross multiply
   3,781.89x = 5,218.79 × 2,103.21
4. Step 4: Simplify right side
   3,781.89x = 10,976,200.80
5. Step 5: Solve for x
   x = 10,976,200.80/3,781.89
6. Step 6: Final answer
   x = 2,902.31