Finding the Fourth Proportional to 111.02, 166.23 and 90.50

Step by Step Solution

1. Step 1: Write the proportion equation
   111.02 : 166.23 = 90.50 : x
2. Step 2: Convert to fraction form
   111.02/166.23 = 90.50/x
3. Step 3: Cross multiply
   111.02x = 166.23 × 90.50
4. Step 4: Simplify right side
   111.02x = 15,043.82
5. Step 5: Solve for x
   x = 15,043.82/111.02
6. Step 6: Final answer
   x = 135.51