Finding the Fourth Proportional to 111.08, 153.31 and 90.30

Step by Step Solution

1. Step 1: Write the proportion equation
   111.08 : 153.31 = 90.30 : x
2. Step 2: Convert to fraction form
   111.08/153.31 = 90.30/x
3. Step 3: Cross multiply
   111.08x = 153.31 × 90.30
4. Step 4: Simplify right side
   111.08x = 13,844.41
5. Step 5: Solve for x
   x = 13,844.41/111.08
6. Step 6: Final answer
   x = 124.64