Finding the Fourth Proportional to 12,150.70, 18,211.42 and 5,128

Step by Step Solution

1. Step 1: Write the proportion equation
   12,150.70 : 18,211.42 = 5,128 : x
2. Step 2: Convert to fraction form
   12,150.70/18,211.42 = 5,128/x
3. Step 3: Cross multiply
   12,150.70x = 18,211.42 × 5,128
4. Step 4: Simplify right side
   12,150.70x = 93,388,161.76
5. Step 5: Solve for x
   x = 93,388,161.76/12,150.70
6. Step 6: Final answer
   x = 7,685.83