Finding the Fourth Proportional to 111.57, 153.96 and 72.19

Step by Step Solution

1. Step 1: Write the proportion equation
   111.57 : 153.96 = 72.19 : x
2. Step 2: Convert to fraction form
   111.57/153.96 = 72.19/x
3. Step 3: Cross multiply
   111.57x = 153.96 × 72.19
4. Step 4: Simplify right side
   111.57x = 11,114.37
5. Step 5: Solve for x
   x = 11,114.37/111.57
6. Step 6: Final answer
   x = 99.62