Finding the Fourth Proportional to 105.91, 146.17 and 64.50

Step by Step Solution

1. Step 1: Write the proportion equation
   105.91 : 146.17 = 64.50 : x
2. Step 2: Convert to fraction form
   105.91/146.17 = 64.50/x
3. Step 3: Cross multiply
   105.91x = 146.17 × 64.50
4. Step 4: Simplify right side
   105.91x = 9,427.50
5. Step 5: Solve for x
   x = 9,427.50/105.91
6. Step 6: Final answer
   x = 89.02