Finding the Fourth Proportional to 111.33, 153.45 and 83.79

Step by Step Solution

1. Step 1: Write the proportion equation
   111.33 : 153.45 = 83.79 : x
2. Step 2: Convert to fraction form
   111.33/153.45 = 83.79/x
3. Step 3: Cross multiply
   111.33x = 153.45 × 83.79
4. Step 4: Simplify right side
   111.33x = 12,857.58
5. Step 5: Solve for x
   x = 12,857.58/111.33
6. Step 6: Final answer
   x = 115.49