Finding the Fourth Proportional to 90,128.42, 135,108.96 and 42,765.78

Step by Step Solution

1. Step 1: Write the proportion equation
   90,128.42 : 135,108.96 = 42,765.78 : x
2. Step 2: Convert to fraction form
   90,128.42/135,108.96 = 42,765.78/x
3. Step 3: Cross multiply
   90,128.42x = 135,108.96 × 42,765.78
4. Step 4: Simplify right side
   90,128.42x = 5,778,040,059.39
5. Step 5: Solve for x
   x = 5,778,040,059.39/90,128.42
6. Step 6: Final answer
   x = 64,108.97