Finding the Fourth Proportional to 111.51, 153.71 and 80.38

Step by Step Solution

1. Step 1: Write the proportion equation
   111.51 : 153.71 = 80.38 : x
2. Step 2: Convert to fraction form
   111.51/153.71 = 80.38/x
3. Step 3: Cross multiply
   111.51x = 153.71 × 80.38
4. Step 4: Simplify right side
   111.51x = 12,355.38
5. Step 5: Solve for x
   x = 12,355.38/111.51
6. Step 6: Final answer
   x = 110.80