Finding the Fourth Proportional to 111.43, 153.74 and 72.09

Step by Step Solution

1. Step 1: Write the proportion equation
   111.43 : 153.74 = 72.09 : x
2. Step 2: Convert to fraction form
   111.43/153.74 = 72.09/x
3. Step 3: Cross multiply
   111.43x = 153.74 × 72.09
4. Step 4: Simplify right side
   111.43x = 11,083.30
5. Step 5: Solve for x
   x = 11,083.30/111.43
6. Step 6: Final answer
   x = 99.46