Finding the Fourth Proportional to 111.33, 153.50 and 90.56

Step by Step Solution

1. Step 1: Write the proportion equation
   111.33 : 153.50 = 90.56 : x
2. Step 2: Convert to fraction form
   111.33/153.50 = 90.56/x
3. Step 3: Cross multiply
   111.33x = 153.50 × 90.56
4. Step 4: Simplify right side
   111.33x = 13,900.51
5. Step 5: Solve for x
   x = 13,900.51/111.33
6. Step 6: Final answer
   x = 124.86