Finding the Fourth Proportional to 139.71, 192.71 and 90.62

Step by Step Solution

1. Step 1: Write the proportion equation
   139.71 : 192.71 = 90.62 : x
2. Step 2: Convert to fraction form
   139.71/192.71 = 90.62/x
3. Step 3: Cross multiply
   139.71x = 192.71 × 90.62
4. Step 4: Simplify right side
   139.71x = 17,461.96
5. Step 5: Solve for x
   x = 17,461.96/139.71
6. Step 6: Final answer
   x = 124.99