Finding the Fourth Proportional to 111.76, 154.20 and 65.12

Step by Step Solution

1. Step 1: Write the proportion equation
   111.76 : 154.20 = 65.12 : x
2. Step 2: Convert to fraction form
   111.76/154.20 = 65.12/x
3. Step 3: Cross multiply
   111.76x = 154.20 × 65.12
4. Step 4: Simplify right side
   111.76x = 10,041.50
5. Step 5: Solve for x
   x = 10,041.50/111.76
6. Step 6: Final answer
   x = 89.85