Finding the Fourth Proportional to 105.82, 145.94 and 78.19

Step by Step Solution

1. Step 1: Write the proportion equation
   105.82 : 145.94 = 78.19 : x
2. Step 2: Convert to fraction form
   105.82/145.94 = 78.19/x
3. Step 3: Cross multiply
   105.82x = 145.94 × 78.19
4. Step 4: Simplify right side
   105.82x = 11,411.05
5. Step 5: Solve for x
   x = 11,411.05/105.82
6. Step 6: Final answer
   x = 107.83