Finding the Fourth Proportional to 128.30, 192.38 and 109.05

Step by Step Solution

1. Step 1: Write the proportion equation
   128.30 : 192.38 = 109.05 : x
2. Step 2: Convert to fraction form
   128.30/192.38 = 109.05/x
3. Step 3: Cross multiply
   128.30x = 192.38 × 109.05
4. Step 4: Simplify right side
   128.30x = 20,978.49
5. Step 5: Solve for x
   x = 20,978.49/128.30
6. Step 6: Final answer
   x = 163.51