Finding the Fourth Proportional to 90,238.32, 134,711.64 and 78,431.76

Step by Step Solution

1. Step 1: Write the proportion equation
   90,238.32 : 134,711.64 = 78,431.76 : x
2. Step 2: Convert to fraction form
   90,238.32/134,711.64 = 78,431.76/x
3. Step 3: Cross multiply
   90,238.32x = 134,711.64 × 78,431.76
4. Step 4: Simplify right side
   90,238.32x = 10,565,671,017.69
5. Step 5: Solve for x
   x = 10,565,671,017.69/90,238.32
6. Step 6: Final answer
   x = 117,086.30