Finding the Fourth Proportional to 3,991.38, 5,507.10 and 2,419.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,991.38 : 5,507.10 = 2,419.20 : x
2. Step 2: Convert to fraction form
   3,991.38/5,507.10 = 2,419.20/x
3. Step 3: Cross multiply
   3,991.38x = 5,507.10 × 2,419.20
4. Step 4: Simplify right side
   3,991.38x = 13,322,776.32
5. Step 5: Solve for x
   x = 13,322,776.32/3,991.38
6. Step 6: Final answer
   x = 3,337.89