Finding the Fourth Proportional to 111.34, 153.65 and 64.72

Step by Step Solution

1. Step 1: Write the proportion equation
   111.34 : 153.65 = 64.72 : x
2. Step 2: Convert to fraction form
   111.34/153.65 = 64.72/x
3. Step 3: Cross multiply
   111.34x = 153.65 × 64.72
4. Step 4: Simplify right side
   111.34x = 9,943.90
5. Step 5: Solve for x
   x = 9,943.90/111.34
6. Step 6: Final answer
   x = 89.31