Finding the Fourth Proportional to 105.83, 145.98 and 78.17

Step by Step Solution

1. Step 1: Write the proportion equation
   105.83 : 145.98 = 78.17 : x
2. Step 2: Convert to fraction form
   105.83/145.98 = 78.17/x
3. Step 3: Cross multiply
   105.83x = 145.98 × 78.17
4. Step 4: Simplify right side
   105.83x = 11,411.26
5. Step 5: Solve for x
   x = 11,411.26/105.83
6. Step 6: Final answer
   x = 107.83