Finding the Fourth Proportional to 105.32, 145.36 and 83.55

Step by Step Solution

1. Step 1: Write the proportion equation
   105.32 : 145.36 = 83.55 : x
2. Step 2: Convert to fraction form
   105.32/145.36 = 83.55/x
3. Step 3: Cross multiply
   105.32x = 145.36 × 83.55
4. Step 4: Simplify right side
   105.32x = 12,144.83
5. Step 5: Solve for x
   x = 12,144.83/105.32
6. Step 6: Final answer
   x = 115.31