Finding the Fourth Proportional to 105.82, 145.87 and 83.65

Step by Step Solution

1. Step 1: Write the proportion equation
   105.82 : 145.87 = 83.65 : x
2. Step 2: Convert to fraction form
   105.82/145.87 = 83.65/x
3. Step 3: Cross multiply
   105.82x = 145.87 × 83.65
4. Step 4: Simplify right side
   105.82x = 12,201.61
5. Step 5: Solve for x
   x = 12,201.61/105.82
6. Step 6: Final answer
   x = 115.31