Finding the Fourth Proportional to 105.58, 145.62 and 72.88

Step by Step Solution

1. Step 1: Write the proportion equation
   105.58 : 145.62 = 72.88 : x
2. Step 2: Convert to fraction form
   105.58/145.62 = 72.88/x
3. Step 3: Cross multiply
   105.58x = 145.62 × 72.88
4. Step 4: Simplify right side
   105.58x = 10,612.79
5. Step 5: Solve for x
   x = 10,612.79/105.58
6. Step 6: Final answer
   x = 100.52