Finding the Fourth Proportional to 128.06, 191.16 and 111.06

Step by Step Solution

1. Step 1: Write the proportion equation
   128.06 : 191.16 = 111.06 : x
2. Step 2: Convert to fraction form
   128.06/191.16 = 111.06/x
3. Step 3: Cross multiply
   128.06x = 191.16 × 111.06
4. Step 4: Simplify right side
   128.06x = 21,229.67
5. Step 5: Solve for x
   x = 21,229.67/128.06
6. Step 6: Final answer
   x = 165.78