Finding the Fourth Proportional to 128,061.36, 191,936.51 and 90,632.37

Step by Step Solution

1. Step 1: Write the proportion equation
   128,061.36 : 191,936.51 = 90,632.37 : x
2. Step 2: Convert to fraction form
   128,061.36/191,936.51 = 90,632.37/x
3. Step 3: Cross multiply
   128,061.36x = 191,936.51 × 90,632.37
4. Step 4: Simplify right side
   128,061.36x = 17,395,660,790.83
5. Step 5: Solve for x
   x = 17,395,660,790.83/128,061.36
6. Step 6: Final answer
   x = 135,838.48