Finding the Fourth Proportional to 8,665.89, 13,002.09 and 5,157.91

Step by Step Solution

1. Step 1: Write the proportion equation
   8,665.89 : 13,002.09 = 5,157.91 : x
2. Step 2: Convert to fraction form
   8,665.89/13,002.09 = 5,157.91/x
3. Step 3: Cross multiply
   8,665.89x = 13,002.09 × 5,157.91
4. Step 4: Simplify right side
   8,665.89x = 67,063,606.94
5. Step 5: Solve for x
   x = 67,063,606.94/8,665.89
6. Step 6: Final answer
   x = 7,738.81