Finding the Fourth Proportional to 105.56, 145.59 and 64.09

Step by Step Solution

1. Step 1: Write the proportion equation
   105.56 : 145.59 = 64.09 : x
2. Step 2: Convert to fraction form
   105.56/145.59 = 64.09/x
3. Step 3: Cross multiply
   105.56x = 145.59 × 64.09
4. Step 4: Simplify right side
   105.56x = 9,330.86
5. Step 5: Solve for x
   x = 9,330.86/105.56
6. Step 6: Final answer
   x = 88.39