Finding the Fourth Proportional to 139.64, 192.56 and 90.52

Step by Step Solution

1. Step 1: Write the proportion equation
   139.64 : 192.56 = 90.52 : x
2. Step 2: Convert to fraction form
   139.64/192.56 = 90.52/x
3. Step 3: Cross multiply
   139.64x = 192.56 × 90.52
4. Step 4: Simplify right side
   139.64x = 17,430.53
5. Step 5: Solve for x
   x = 17,430.53/139.64
6. Step 6: Final answer
   x = 124.82