Finding the Fourth Proportional to 12,213.56, 18,308.03 and 4,815.15

Step by Step Solution

1. Step 1: Write the proportion equation
   12,213.56 : 18,308.03 = 4,815.15 : x
2. Step 2: Convert to fraction form
   12,213.56/18,308.03 = 4,815.15/x
3. Step 3: Cross multiply
   12,213.56x = 18,308.03 × 4,815.15
4. Step 4: Simplify right side
   12,213.56x = 88,155,886.58
5. Step 5: Solve for x
   x = 88,155,886.58/12,213.56
6. Step 6: Final answer
   x = 7,217.87