Finding the Fourth Proportional to 111.24, 153.72 and 91.80

Step by Step Solution

1. Step 1: Write the proportion equation
   111.24 : 153.72 = 91.80 : x
2. Step 2: Convert to fraction form
   111.24/153.72 = 91.80/x
3. Step 3: Cross multiply
   111.24x = 153.72 × 91.80
4. Step 4: Simplify right side
   111.24x = 14,111.50
5. Step 5: Solve for x
   x = 14,111.50/111.24
6. Step 6: Final answer
   x = 126.86