Finding the Fourth Proportional to 12,071.48, 16,638.72 and 8,091.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,071.48 : 16,638.72 = 8,091.20 : x
2. Step 2: Convert to fraction form
   12,071.48/16,638.72 = 8,091.20/x
3. Step 3: Cross multiply
   12,071.48x = 16,638.72 × 8,091.20
4. Step 4: Simplify right side
   12,071.48x = 134,627,211.26
5. Step 5: Solve for x
   x = 134,627,211.26/12,071.48
6. Step 6: Final answer
   x = 11,152.50