Finding the Fourth Proportional to 8,408.68, 12,599.18 and 5,111.80

Step by Step Solution

1. Step 1: Write the proportion equation
   8,408.68 : 12,599.18 = 5,111.80 : x
2. Step 2: Convert to fraction form
   8,408.68/12,599.18 = 5,111.80/x
3. Step 3: Cross multiply
   8,408.68x = 12,599.18 × 5,111.80
4. Step 4: Simplify right side
   8,408.68x = 64,404,488.32
5. Step 5: Solve for x
   x = 64,404,488.32/8,408.68
6. Step 6: Final answer
   x = 7,659.29