Finding the Fourth Proportional to 8,718.54, 13,059.15 and 8,111.64

Step by Step Solution

1. Step 1: Write the proportion equation
   8,718.54 : 13,059.15 = 8,111.64 : x
2. Step 2: Convert to fraction form
   8,718.54/13,059.15 = 8,111.64/x
3. Step 3: Cross multiply
   8,718.54x = 13,059.15 × 8,111.64
4. Step 4: Simplify right side
   8,718.54x = 105,931,123.51
5. Step 5: Solve for x
   x = 105,931,123.51/8,718.54
6. Step 6: Final answer
   x = 12,150.10