Finding the Fourth Proportional to 105.72, 158.34 and 64.95

Step by Step Solution

1. Step 1: Write the proportion equation
   105.72 : 158.34 = 64.95 : x
2. Step 2: Convert to fraction form
   105.72/158.34 = 64.95/x
3. Step 3: Cross multiply
   105.72x = 158.34 × 64.95
4. Step 4: Simplify right side
   105.72x = 10,284.18
5. Step 5: Solve for x
   x = 10,284.18/105.72
6. Step 6: Final answer
   x = 97.28