Finding the Fourth Proportional to 13,633.86, 18,812.61 and 7,665.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,633.86 : 18,812.61 = 7,665.78 : x
2. Step 2: Convert to fraction form
   13,633.86/18,812.61 = 7,665.78/x
3. Step 3: Cross multiply
   13,633.86x = 18,812.61 × 7,665.78
4. Step 4: Simplify right side
   13,633.86x = 144,213,329.49
5. Step 5: Solve for x
   x = 144,213,329.49/13,633.86
6. Step 6: Final answer
   x = 10,577.59