Finding the Fourth Proportional to 111.33, 153.60 and 64.71

Step by Step Solution

1. Step 1: Write the proportion equation
   111.33 : 153.60 = 64.71 : x
2. Step 2: Convert to fraction form
   111.33/153.60 = 64.71/x
3. Step 3: Cross multiply
   111.33x = 153.60 × 64.71
4. Step 4: Simplify right side
   111.33x = 9,939.46
5. Step 5: Solve for x
   x = 9,939.46/111.33
6. Step 6: Final answer
   x = 89.28