Finding the Fourth Proportional to 139.64, 192.69 and 83.61

Step by Step Solution

1. Step 1: Write the proportion equation
   139.64 : 192.69 = 83.61 : x
2. Step 2: Convert to fraction form
   139.64/192.69 = 83.61/x
3. Step 3: Cross multiply
   139.64x = 192.69 × 83.61
4. Step 4: Simplify right side
   139.64x = 16,110.50
5. Step 5: Solve for x
   x = 16,110.50/139.64
6. Step 6: Final answer
   x = 115.37