Finding the Fourth Proportional to 3,886.47, 5,363.31 and 2,118.09

Step by Step Solution

1. Step 1: Write the proportion equation
   3,886.47 : 5,363.31 = 2,118.09 : x
2. Step 2: Convert to fraction form
   3,886.47/5,363.31 = 2,118.09/x
3. Step 3: Cross multiply
   3,886.47x = 5,363.31 × 2,118.09
4. Step 4: Simplify right side
   3,886.47x = 11,359,973.28
5. Step 5: Solve for x
   x = 11,359,973.28/3,886.47
6. Step 6: Final answer
   x = 2,922.95