Finding the Fourth Proportional to 90,778.72, 136,171.73 and 31,620.37

Step by Step Solution

1. Step 1: Write the proportion equation
   90,778.72 : 136,171.73 = 31,620.37 : x
2. Step 2: Convert to fraction form
   90,778.72/136,171.73 = 31,620.37/x
3. Step 3: Cross multiply
   90,778.72x = 136,171.73 × 31,620.37
4. Step 4: Simplify right side
   90,778.72x = 4,305,800,486.14
5. Step 5: Solve for x
   x = 4,305,800,486.14/90,778.72
6. Step 6: Final answer
   x = 47,431.83