Finding the Fourth Proportional to 3,993.71, 5,499.43 and 3,905.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,993.71 : 5,499.43 = 3,905.20 : x
2. Step 2: Convert to fraction form
   3,993.71/5,499.43 = 3,905.20/x
3. Step 3: Cross multiply
   3,993.71x = 5,499.43 × 3,905.20
4. Step 4: Simplify right side
   3,993.71x = 21,476,354.51
5. Step 5: Solve for x
   x = 21,476,354.51/3,993.71
6. Step 6: Final answer
   x = 5,377.55