Finding the Fourth Proportional to 3,892.12, 5,371.59 and 2,213.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,892.12 : 5,371.59 = 2,213.78 : x
2. Step 2: Convert to fraction form
   3,892.12/5,371.59 = 2,213.78/x
3. Step 3: Cross multiply
   3,892.12x = 5,371.59 × 2,213.78
4. Step 4: Simplify right side
   3,892.12x = 11,891,518.51
5. Step 5: Solve for x
   x = 11,891,518.51/3,892.12
6. Step 6: Final answer
   x = 3,055.28