Finding the Fourth Proportional to 8,139.81, 12,213.52 and 2,878.81

Step by Step Solution

1. Step 1: Write the proportion equation
   8,139.81 : 12,213.52 = 2,878.81 : x
2. Step 2: Convert to fraction form
   8,139.81/12,213.52 = 2,878.81/x
3. Step 3: Cross multiply
   8,139.81x = 12,213.52 × 2,878.81
4. Step 4: Simplify right side
   8,139.81x = 35,160,403.51
5. Step 5: Solve for x
   x = 35,160,403.51/8,139.81
6. Step 6: Final answer
   x = 4,319.56