Finding the Fourth Proportional to 8,971.86, 13,436.94 and 8,660.42

Step by Step Solution

1. Step 1: Write the proportion equation
   8,971.86 : 13,436.94 = 8,660.42 : x
2. Step 2: Convert to fraction form
   8,971.86/13,436.94 = 8,660.42/x
3. Step 3: Cross multiply
   8,971.86x = 13,436.94 × 8,660.42
4. Step 4: Simplify right side
   8,971.86x = 116,369,510.88
5. Step 5: Solve for x
   x = 116,369,510.88/8,971.86
6. Step 6: Final answer
   x = 12,970.49