Finding the Fourth Proportional to 105.76, 145.86 and 72.94

Step by Step Solution

1. Step 1: Write the proportion equation
   105.76 : 145.86 = 72.94 : x
2. Step 2: Convert to fraction form
   105.76/145.86 = 72.94/x
3. Step 3: Cross multiply
   105.76x = 145.86 × 72.94
4. Step 4: Simplify right side
   105.76x = 10,639.03
5. Step 5: Solve for x
   x = 10,639.03/105.76
6. Step 6: Final answer
   x = 100.60