Finding the Fourth Proportional to 111.61, 153.88 and 90.85

Step by Step Solution

1. Step 1: Write the proportion equation
   111.61 : 153.88 = 90.85 : x
2. Step 2: Convert to fraction form
   111.61/153.88 = 90.85/x
3. Step 3: Cross multiply
   111.61x = 153.88 × 90.85
4. Step 4: Simplify right side
   111.61x = 13,980.00
5. Step 5: Solve for x
   x = 13,980.00/111.61
6. Step 6: Final answer
   x = 125.26