Finding the Third Proportional to 7,642.50 and 11,815.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,642.50 : 11,815.50 = 11,815.50 : x
2. Step 2: Convert to fraction form
   7,642.50/11,815.50 = 11,815.50/x
3. Step 3: Cross multiply
   7,642.50x = 11,815.50 × 11,815.50
4. Step 4: Simplify right side
   7,642.50x = 139,606,040.25
5. Step 5: Solve for x
   x = 139,606,040.25/7,642.50
6. Step 6: Final answer
   x = 18,267.06