Finding the Fourth Proportional to 137.91, 190.17 and 105.15

Step by Step Solution

1. Step 1: Write the proportion equation
   137.91 : 190.17 = 105.15 : x
2. Step 2: Convert to fraction form
   137.91/190.17 = 105.15/x
3. Step 3: Cross multiply
   137.91x = 190.17 × 105.15
4. Step 4: Simplify right side
   137.91x = 19,996.38
5. Step 5: Solve for x
   x = 19,996.38/137.91
6. Step 6: Final answer
   x = 145.00