Finding the Fourth Proportional to 13,279.78, 18,326.46 and 7,615

Step by Step Solution

1. Step 1: Write the proportion equation
   13,279.78 : 18,326.46 = 7,615 : x
2. Step 2: Convert to fraction form
   13,279.78/18,326.46 = 7,615/x
3. Step 3: Cross multiply
   13,279.78x = 18,326.46 × 7,615
4. Step 4: Simplify right side
   13,279.78x = 139,555,992.90
5. Step 5: Solve for x
   x = 139,555,992.90/13,279.78
6. Step 6: Final answer
   x = 10,508.91