Finding the Fourth Proportional to 139.10, 191.86 and 89.96

Step by Step Solution

1. Step 1: Write the proportion equation
   139.10 : 191.86 = 89.96 : x
2. Step 2: Convert to fraction form
   139.10/191.86 = 89.96/x
3. Step 3: Cross multiply
   139.10x = 191.86 × 89.96
4. Step 4: Simplify right side
   139.10x = 17,260.21
5. Step 5: Solve for x
   x = 17,260.21/139.10
6. Step 6: Final answer
   x = 124.09