Finding the Fourth Proportional to 105.68, 145.82 and 89.15

Step by Step Solution

1. Step 1: Write the proportion equation
   105.68 : 145.82 = 89.15 : x
2. Step 2: Convert to fraction form
   105.68/145.82 = 89.15/x
3. Step 3: Cross multiply
   105.68x = 145.82 × 89.15
4. Step 4: Simplify right side
   105.68x = 12,999.41
5. Step 5: Solve for x
   x = 12,999.41/105.68
6. Step 6: Final answer
   x = 123.01