Finding the Fourth Proportional to 105.32, 145.42 and 72.66

Step by Step Solution

1. Step 1: Write the proportion equation
   105.32 : 145.42 = 72.66 : x
2. Step 2: Convert to fraction form
   105.32/145.42 = 72.66/x
3. Step 3: Cross multiply
   105.32x = 145.42 × 72.66
4. Step 4: Simplify right side
   105.32x = 10,566.22
5. Step 5: Solve for x
   x = 10,566.22/105.32
6. Step 6: Final answer
   x = 100.32