Finding the Fourth Proportional to 11,820.24, 17,724.31 and 3,919.90

Step by Step Solution

1. Step 1: Write the proportion equation
   11,820.24 : 17,724.31 = 3,919.90 : x
2. Step 2: Convert to fraction form
   11,820.24/17,724.31 = 3,919.90/x
3. Step 3: Cross multiply
   11,820.24x = 17,724.31 × 3,919.90
4. Step 4: Simplify right side
   11,820.24x = 69,477,522.77
5. Step 5: Solve for x
   x = 69,477,522.77/11,820.24
6. Step 6: Final answer
   x = 5,877.84