Finding the Fourth Proportional to 12,091.55, 18,128.81 and 4,689.77

Step by Step Solution

1. Step 1: Write the proportion equation
   12,091.55 : 18,128.81 = 4,689.77 : x
2. Step 2: Convert to fraction form
   12,091.55/18,128.81 = 4,689.77/x
3. Step 3: Cross multiply
   12,091.55x = 18,128.81 × 4,689.77
4. Step 4: Simplify right side
   12,091.55x = 85,019,870.35
5. Step 5: Solve for x
   x = 85,019,870.35/12,091.55
6. Step 6: Final answer
   x = 7,031.35