Finding the Fourth Proportional to 111.60, 153.98 and 64.96

Step by Step Solution

1. Step 1: Write the proportion equation
   111.60 : 153.98 = 64.96 : x
2. Step 2: Convert to fraction form
   111.60/153.98 = 64.96/x
3. Step 3: Cross multiply
   111.60x = 153.98 × 64.96
4. Step 4: Simplify right side
   111.60x = 10,002.54
5. Step 5: Solve for x
   x = 10,002.54/111.60
6. Step 6: Final answer
   x = 89.63