Finding the Fourth Proportional to 111.57, 154.01 and 64.98

Step by Step Solution

1. Step 1: Write the proportion equation
   111.57 : 154.01 = 64.98 : x
2. Step 2: Convert to fraction form
   111.57/154.01 = 64.98/x
3. Step 3: Cross multiply
   111.57x = 154.01 × 64.98
4. Step 4: Simplify right side
   111.57x = 10,007.57
5. Step 5: Solve for x
   x = 10,007.57/111.57
6. Step 6: Final answer
   x = 89.70