Finding the Fourth Proportional to 139.67, 192.69 and 90.56

Step by Step Solution

1. Step 1: Write the proportion equation
   139.67 : 192.69 = 90.56 : x
2. Step 2: Convert to fraction form
   139.67/192.69 = 90.56/x
3. Step 3: Cross multiply
   139.67x = 192.69 × 90.56
4. Step 4: Simplify right side
   139.67x = 17,449.04
5. Step 5: Solve for x
   x = 17,449.04/139.67
6. Step 6: Final answer
   x = 124.93