Finding the Fourth Proportional to 139.69, 192.74 and 90.56

Step by Step Solution

1. Step 1: Write the proportion equation
   139.69 : 192.74 = 90.56 : x
2. Step 2: Convert to fraction form
   139.69/192.74 = 90.56/x
3. Step 3: Cross multiply
   139.69x = 192.74 × 90.56
4. Step 4: Simplify right side
   139.69x = 17,454.08
5. Step 5: Solve for x
   x = 17,454.08/139.69
6. Step 6: Final answer
   x = 124.95