Finding the Fourth Proportional to 111.72, 154.17 and 65.10

Step by Step Solution

1. Step 1: Write the proportion equation
   111.72 : 154.17 = 65.10 : x
2. Step 2: Convert to fraction form
   111.72/154.17 = 65.10/x
3. Step 3: Cross multiply
   111.72x = 154.17 × 65.10
4. Step 4: Simplify right side
   111.72x = 10,036.47
5. Step 5: Solve for x
   x = 10,036.47/111.72
6. Step 6: Final answer
   x = 89.84