Finding the Fourth Proportional to 12,919.50, 19,379.61 and 4,155.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,919.50 : 19,379.61 = 4,155.30 : x
2. Step 2: Convert to fraction form
   12,919.50/19,379.61 = 4,155.30/x
3. Step 3: Cross multiply
   12,919.50x = 19,379.61 × 4,155.30
4. Step 4: Simplify right side
   12,919.50x = 80,528,093.43
5. Step 5: Solve for x
   x = 80,528,093.43/12,919.50
6. Step 6: Final answer
   x = 6,233.07